Dr. Jeff Masters' WunderBlog

Red River rising: 18th consecutive year of flooding--why?

Posted by: Dr. Jeff Masters, 19. maaliskuuta 2010 klo 15:08 (GMT)

The Red River at Fargo, North Dakota continues to rise, with a peak expected Sunday at the 4th highest flood level observed in the past century. "Major" flood level is 30 feet, which the river surpassed on Wednesday, and the river is expected to crest near 38 feet on Sunday, just 2.8 feet below the record set last year. Flood stage is eighteen feet, and the Red River has now reached flood stage at Fargo for eighteen consecutive years, according to the U.S. Army Corps of Engineers. Prior to this remarkable stretch of flooding (which began in 1993), the river flooded in just 29 of 90 years. This year's flood is rated as somewhere between a 50-year and 100-year flood. Last year's record flood was a 100-year flood. The U.S. Army Corps of Engineers lists the 10-year flood level for the Red River at Fargo to be 10,300 cubic feet per second. A 10-year flood, historically, has a 10% chance of occurring in a given year. In the last twenty years, the Red River has had eight 10-year floods--one every 2.5 years, on average. This year is the fourth year out of the past five with a 10-year flood. Clearly, flooding has increased significantly along the Red River over the past twenty years.

Figure 1. Current and forecast flood stage for the Red River of the North at Fargo, ND. You can access images like these using our wundermap for Fargo with the "USGS River" layer turned on. Click on the icon for USGS station 05054000, then hit the "click for graph" link.

Reasons for flooding: landform factors
According the U.S. Geological Survey, the unique landform characteristics of the Red River Valley make it highly susceptible to flooding. These factors include:

1) A relatively shallow and meandering river channel--a shallow channel holds less water and the meandering can cause flow to slow down as the channel makes its turns, causing over-bank flooding.

2) A gentle slope (averaging 0.5 to 1.5 feet per mile) that inhibits channel flow and encourages overland flooding or water "ponding" (especially on even, saturated ground) in the basin.

3) The northerly direction of flow--flow in the Red River travels from south (upstream) to north (downstream). The direction of flow becomes a critical factor in the spring when the southern (upstream) part of the Red River has thawed and the northern (downstream) part of the channel is still frozen. As water moves north toward the still frozen river channel, ice jams and substantial backwater flow and flooding can occur.

Figure 2. Peak flow of the Red River at Fargo, North Dakota through time. The two largest flow rates occurred last year (2009), and in 1997. The projected crest for Sunday (red circle) would be fourth greatest flood since reliable records began in 1901. Image credit: U.S. Geological Survey.

Reasons for this year's flood: highly unfavorable weather conditions
The USGS also cites five weather factors that can act to enhance flooding along the Red River. All five of these factors occurred to a significant degree this year:

1) Above-normal amounts of precipitation in the fall of the year that produce high levels of soil moisture, particularly in flat surface areas, in the basin. North Dakota had its 22nd wettest fall in the 115-year record in 2009.

2) Freezing of saturated ground in late fall or early winter, before significant snowfall occurs, that produces a hard, deep frost that limits infiltration of runoff during snowmelt. Fargo had a November that was much warmer than average, followed by a sudden plunge to below-zero temperatures by the second week of December. This froze the saturated ground to a great depth.

3) Above-normal winter snowfall in the basin. North Dakota had a top 15% winter for precipitation, with the period December 2009 - February 2010 ranking 15th wettest in the past 115 years.

4) Above-normal precipitation during snowmelt. Precipitation for March 1 - 18 has been 1.41", compared to the average of 0.61".

5) Above-normal temperatures during snowmelt. High temperatures in Fargo have averaged 6°F warmer than normal for March 1 - 18.

Urbanization increases flooding
Urbanization has had a major impact on increasing flooding not only along the Red River, but in every river basin in the U.S. Many cities and developed areas are located in flood plains next to major rivers and their tributaries. Highways, streets, parking lots, sidewalks, and buildings now cover large areas of the ground that used to absorb excess rain water and slow the rate at which run-off from precipitation and melting snow reached rivers. By developing large portions of our flood plains, run-off now reaches rivers more quickly, generating higher floods.

Building levees and flood defenses increases flood peaks
Defending ourselves against floods has made floods worse. Every time a new levee is built, or an old floodwall raised in height to prevent overtopping, more and more water is forced into the river bed, which raises the height of the flood. Flood waters that used to be able to spread out over their natural flood plains are now forbidden from spilling out over newly developed land in flood plains. For example, proposed improvements to the flood defense system in Fargo could cause a 4 - 10 inch rise in floods immediately downstream from the city, according to the Army Corps of Engineers.

Precipitation is increasing
As the climate warms, evaporation of moisture from the oceans increases, resulting in more water vapor in the air. According to the 2007 IPCC report, water vapor in the global atmosphere has increased by about 5% over the 20th century, and 4% since 1970. Satellite measurements (Trenberth et al., 2005) have shown a 1.3% per decade increase in water vapor over the global oceans since 1988. Santer et al. (2007) used a climate model to study the relative contribution of natural and human-caused effects on increasing water vapor, and concluded that this increase was "primarily due to human-caused increases in greenhouse gases". This was also the conclusion of Willet et al. (2007). This increase in water vapor has very likely led to an increase in global precipitation. For instance, over the U.S., where we have very good precipitation records, annual average precipitation has increased 7% over the past century (Groisman et al., 2004). Precipitation over the Red River drainage basin increased by about 10 - 20% during the 20th Century (Figure 3.) The same study also found a 14% increase in heavy (top 5%) and 20% increase in very heavy (top 1%) precipitation events over the U.S. in the past century. These are the type of events most likely to cause flooding. Kunkel et al. (2003) also found an increase in heavy precipitation events over the U.S. in recent decades, but noted that heavy precipitation events were nearly as frequent at the end of the 19th century and beginning of the 20th century, though the data is not as reliable back then.

Figure 3. Change in precipitation over the U.S. between 1900 - 2000, from the U.S. Cooperative network. Precipitation in the Red River drainage area increased by 10 - 20% over the 20th century. Image credit: Contemporary Changes of the Hydrological Cycle over the Contiguous United States: Trends (Groisman et al., 2002).

The future of flooding
As the population continues to expand, development in flood plains and construction of new levees and flood protection systems will continue to push floods to higher heights. With global warming expected to continue and drive ever higher precipitation amounts--falling preferentially in heavy precipitation events--it is highly probable that flooding in the Red River Valley--and over most of the northern 2/3 of the U.S. where precipitation increases are likely--will see higher and more frequent floods. With these higher and more frequent floods comes the increased risk of multi-billion dollar disasters, when a record flood event overwhelms flood defenses and inundates huge areas of developed flood plains. Obviously, we need to make smart decisions to limit development in flood plains to reduce the cost and suffering of these future flooding disasters.

References
Kunkel, K. E., D. R. Easterling, K. Redmond, and K. Hubbard, 2003, "Temporal variations of extreme precipitation events in the United States: 1895.2000", Geophys. Res. Lett., 30(17), 1900, doi:10.1029/2003GL018052.

Groisman, P.Y., R.W. Knight, T.R. Karl, D.R. Easterling, B. Sun, and J.H. Lawrimore, 2004, "Contemporary Changes of the Hydrological Cycle over the Contiguous United States: Trends Derived from In Situ Observations," J. Hydrometeor., 5, 64.85.

Milly, P.C.D., R.T. Wetherald, K.A. Dunne, and T.L.Delworth, Increasing risk of great floods in a changing climate", Nature 415, 514-517 (31 January 2002) | doi:10.1038/415514a.

Santer, B.D., C. Mears, F. J. Wentz, K. E. Taylor, P. J. Gleckler, T. M. L. Wigley, T. P. Barnett, J. S. Boyle, W. Brüggemann, N. P. Gillett, S. A. Klein, G. A. Meehl, T. Nozawa, D. W. Pierce, P. A. Stott, W. M. Washington, and M. F. Wehner, 2007, "Identification of human-induced changes in atmospheric moisture content", PNAS 2007 104: 15248-15253.

Trenberth, K.E., J. Fasullo, and L. Smith, 2005: "Trends and variability in column-integrated atmospheric water vapor", Climate Dynamics 24, 741-758.

Willett, K.M., N.P. Gillett, P.D. Jones, and P.W. Thorne, 2007, "Attribution of observed surface humidity changes to human influence", Nature 449, 710-712 (11 October 2007) | doi:10.1038/nature06207.

Links
A good way to track the flooding event is to use our wundermap for the Red River with the USGS River layer turned on.

The Fargo Flood webpage of North Dakota State University, Fargo, has some excellent links.

I'll have a new post on Monday or Tuesday.

Jeff Masters

Red River Flood 2006 (mw25)

The water level of the Red River when I took this photo was 47.2 feet, 19.2 feet above flood stage and the 6th highest level in Grand Forks' history. The river is expected to crest at 47.4 feet on Wednesday morning. Luckily, no homes have been lost in the Grand Forks area as of yet due to the flooding.

Fargo Flood 2009 - Elm & 15th Ave. N. (tliebenow)

Picture says it all. Clay dike built to contain the Red River in North Fargo.

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1051. tornadodude 22. maaliskuuta 2010 klo 15:47 (GMT)
Quoting NttyGrtty: Some cats have better night vision than others. Yes, that's WAY off topic but since we seem to be discussing healthcare in here today, I thought what the heck, why not cat vision too. LOL that was great howdy all Member Since: 28.06.2006 Posts: 22 Comments: 7816

1052. hydrus 22. maaliskuuta 2010 klo 15:50 (GMT)
Quoting tornadodude: LOL that was great howdy all Hey T-Dude wuzup Member Since: 27.09.2007 Posts: 1 Comments: 14671

1053. StormChaser81 22. maaliskuuta 2010 klo 15:51 (GMT)
Quoting Tropicsweatherpr: The latest Climate Prediction Center numbers of ENSO show no changes. Nino 4= 1.1C Nino3-4= 1.2C Nino3= 0.7C Nino=1-2=-0.1C Very different Member Since: 11.08.2008 Posts: 0 Comments: 2315

1054. tornadodude 22. maaliskuuta 2010 klo 15:55 (GMT)
Quoting hydrus: Hey T-Dude wuzup oh back to school after spring break last week :p and excited for basketball, Purdue is in the sweet 16, and my high school I went to is playing for the state championship on saturday for basketball whats new with you? Member Since: 28.06.2006 Posts: 22 Comments: 7816

1055. Levi32 22. maaliskuuta 2010 klo 15:59 (GMT)
Wow the new Japanese forecast really takes a dive into this La Nina quite fast: June-July-August: The forecast is still really wet for the Atlantic: Member Since: 24.11.2005 Posts: 593 Comments: 25604

1056. Levi32 22. maaliskuuta 2010 klo 16:01 (GMT)
New March ECMWF operational model nino plume forecast: Member Since: 24.11.2005 Posts: 593 Comments: 25604

1058. hydrus 22. maaliskuuta 2010 klo 16:03 (GMT)
Quoting tornadodude: oh back to school after spring break last week :p and excited for basketball, Purdue is in the sweet 16, and my high school I went to is playing for the state championship on saturday for basketball whats new with you? Congratulations on your teams successful season thus far.I am taking care of my Mom,Pop,dogs, guitar lessons and what ever else needs to be done. It seems that everybody is in general agreement that this hurricane season will be above average. what is you thinking at this time? Member Since: 27.09.2007 Posts: 1 Comments: 14671

1059. Levi32 22. maaliskuuta 2010 klo 16:05 (GMT)
Quoting StormW: Levi, Can you hook me up with the site? Here ya go Member Since: 24.11.2005 Posts: 593 Comments: 25604

1060. Levi32 22. maaliskuuta 2010 klo 16:06 (GMT)
New ECMWF operational model March forecasts are pretty much as nasty as the EUROSIP: MSLP: Precipitation: SSTs: Member Since: 24.11.2005 Posts: 593 Comments: 25604

1061. tornadodude 22. maaliskuuta 2010 klo 16:08 (GMT)
Quoting hydrus: Congratulations on your teams successful season thus far.I am taking care of my Mom,Pop,dogs, guitar lessons and what ever else needs to be done. It seems that everybody is in general agreement that this hurricane season will be above average. what is you thinking at this time? hmm yeah I think it will be above average as well, especially if La Nina or Neutral conditions develop in a timely manner Member Since: 28.06.2006 Posts: 22 Comments: 7816

1062. hydrus 22. maaliskuuta 2010 klo 16:13 (GMT)
Quoting tornadodude: hmm yeah I think it will be above average as well, especially if La Nina or Neutral conditions develop in a timely manner I think it will be very active also. The water temps look impressive, excluding the Gulf of Mexico which will warm up by the beginning of hurricane season. Member Since: 27.09.2007 Posts: 1 Comments: 14671

1064. weathermanwannabe 22. maaliskuuta 2010 klo 16:20 (GMT)
Afternoon Folks. SST's will be a given this year, as they are every Summer....What will be most interesting to watch this year, which cannot be accurately predicted too far out, is what sheer levels will be in the Carib during the start of the season in June/July. Have to wait for that one to see if we will have a few early season storms. Member Since: 8.08.2006 Posts: 0 Comments: 6857

1065. jeffs713 22. maaliskuuta 2010 klo 16:24 (GMT)
Quoting Levi32: New ECMWF operational model March forecasts are pretty much as nasty as the EUROSIP: MSLP: Precipitation: SSTs: Why not just put a huge bulls-eye on the Gulf and SE coast this Atlantic season? Sheesh... Member Since: 3.08.2008 Posts: 15 Comments: 5729

1066. tornadodude 22. maaliskuuta 2010 klo 16:24 (GMT)
Quoting hydrus: I think it will be very active also. The water temps look impressive, excluding the Gulf of Mexico which will warm up by the beginning of hurricane season. yeah I know what you mean Member Since: 28.06.2006 Posts: 22 Comments: 7816

1068. belizeit 22. maaliskuuta 2010 klo 16:30 (GMT)
Levi32 the map shows for a lot of precipitation in central america but we have it way below normal . we only have had about .08 inches of rain so far for march . Member Since: 10.01.2010 Posts: 0 Comments: 843

1070. tornadodude 22. maaliskuuta 2010 klo 16:38 (GMT)
Member Since: 28.06.2006 Posts: 22 Comments: 7816

1071. Levi32 22. maaliskuuta 2010 klo 16:39 (GMT)
Ok so since 1950 there have only been 3 years with a moderate-strong La Nina during the hurricane season coming right off of a moderate-strong El Nino the previous winter. They were 1973, 1988, and 1998. Here is what they looked like: Precipitation: (1973 on left, 1988 on right, 1998 on bottom) Sea Surface Temperatures: (order same as above, note 1973 is reanalysis) These are what the hurricane seasons looked like: ~~~~~~~~~~~~~~~~~~~~~~~~~~~ Notice the above-normal areas of precipitation in the Caribbean and Gulf of Mexico. For some reason 1973 was a non-season (haven't researched it) but 1988 had the cold over warm signature in the Atlantic SSTs, and that year was heavily weighted towards the Caribbean, with a lot of southerly tracks through there, including Gilbert. The 1998 season was weighted further north over the SW Atlantic due to the whole ocean being warmer during the summer, but still had the main track congregation quite far west. This was a healthy Cape Verde season, and two storms still battered the Caribbean, the famous Georges and Mitch. Overall, you can see the south and westward congregations of tracks during these seasons, and the danger that these kind of years can pose to land, both the Caribbean and the United States. Member Since: 24.11.2005 Posts: 593 Comments: 25604

1072. belizeit 22. maaliskuuta 2010 klo 16:39 (GMT)
Quoting StormW: That's because the forecast is for July, Aug and Sep. Oh alright thanks . I don't know how long these dry conditions will last for us but if rain season will start in may as it usually does the we should see it dryer this year then the year hurricane Mitch was . That was the driest year i can recall for Belize Member Since: 10.01.2010 Posts: 0 Comments: 843

1073. jeffs713 22. maaliskuuta 2010 klo 16:41 (GMT)
Quoting belizeit: Levi32 the map shows for a lot of precipitation in central america but we have it way below normal . we only have had about .08 inches of rain so far for march . Most of the Caribbean has been very dry this winter. The ECMWF forecast is for this summer, which is looking to be very wet. Member Since: 3.08.2008 Posts: 15 Comments: 5729

1074. tornadodude 22. maaliskuuta 2010 klo 16:43 (GMT)
Member Since: 28.06.2006 Posts: 22 Comments: 7816

1075. Levi32 22. maaliskuuta 2010 klo 16:45 (GMT)
Quoting belizeit: Oh alright thanks . I don't know how long these dry conditions will last for us but if rain season will start in may as it usually does the we should see it dryer this year then the year hurricane Mitch was . That was the driest year i can recall for Belize Yeah you all in Central America and the Caribbean should see a turn-around in precipitation this summer as El Nino reverses and the pattern favors more wetness for you guys. Hopefully that rain won't have to come in the form of major hurricanes. Member Since: 24.11.2005 Posts: 593 Comments: 25604

1077. belizeit 22. maaliskuuta 2010 klo 16:46 (GMT)
Quoting jeffs713: Most of the Caribbean has been very dry this winter. The ECMWF forecast is for this summer, which is looking to be very wet. Our winter here was very wet we had large crop failures due to rain but in mid February the rain stopped and it has not rained since except for a drizzle Member Since: 10.01.2010 Posts: 0 Comments: 843

1078. belizeit 22. maaliskuuta 2010 klo 16:48 (GMT)
Quoting Levi32: Yeah you all in Central America and the Caribbean should see a turn-around in precipitation this summer as El Nino reverses and the pattern favors more wetness for you guys. Hopefully that rain won't have to come in the form of major hurricanes. In our part of Belize we have not had a hurricane since huricane hatie 1960 155 mph winds Member Since: 10.01.2010 Posts: 0 Comments: 843

1079. kimoskee 22. maaliskuuta 2010 klo 16:51 (GMT)
Don't know if we can last until the summer for rain. It's chronic here in Jamaica. Member Since: 17.08.2008 Posts: 0 Comments: 670

1080. Levi32 22. maaliskuuta 2010 klo 16:51 (GMT)
Quoting StormW: Levi, What were your favorite analog years again? I got looking last night, and just by the ONI info, there are really only two that interest me right now...1995 and 1998. Yeah those are the best ONI analogs. I would have to stick 1964 in there with 1995 and 1998 as my favorites out of the package. 1966 is another good one that I like a lot but it stays neutral through the hurricane season and the following year. Member Since: 24.11.2005 Posts: 593 Comments: 25604

1081. belizeit 22. maaliskuuta 2010 klo 16:52 (GMT)
Quoting kimoskee: Don't know if we can last until the summer for rain. It's chronic here in Jamaica. Quoting kimoskee: Don't know if we can last until the summer for rain. It's chronic here in Jamaica. From where does Jamaica get its potable water ? Member Since: 10.01.2010 Posts: 0 Comments: 843

1083. Levi32 22. maaliskuuta 2010 klo 17:00 (GMT)
Quoting StormW: Thanks. Ya...I'm trying to stick with analogs since 1995...when the upswing in activity started. Yeah, I'm weighting those more myself. 2007 would be the next closest one since 1995. It's too bad we don't have ONI from the 1930s and 1940s. There are some good analogs from back during the last time we were at this point in the climate cycle. Member Since: 24.11.2005 Posts: 593 Comments: 25604

1084. Levi32 22. maaliskuuta 2010 klo 17:05 (GMT)
One thing going for the 1960s though is that Sahel rainfall was still above normal during the early-mid part of that decade. We have been below normal since then, and are just now about to come back up into the moist cycle. Member Since: 24.11.2005 Posts: 593 Comments: 25604

1085. FloridaTigers 22. maaliskuuta 2010 klo 17:07 (GMT)
When should we see this current upswing in Atlantic cyclone activity begin to decline? Member Since: 17.05.2009 Posts: 0 Comments: 559

1087. Levi32 22. maaliskuuta 2010 klo 17:16 (GMT)
Quoting FloridaTigers: When should we see this current upswing in Atlantic cyclone activity begin to decline? Well, the AMO (Atlantic Multidecadal Oscillation) just went positive in 1995, which is when the upswing in activity started, and based on past observation, AMO warm cycles last 30-40 years, so we could potentially be seeing a warm Atlantic for the next 20 years or so. This, coupled with a cold PDO, is bad news for us in the countries along the Atlantic. The last time this overlap happened was in the mid-1940s through the early 1960s. This period was pretty bad for the United States. Member Since: 24.11.2005 Posts: 593 Comments: 25604

1088. Levi32 22. maaliskuuta 2010 klo 17:22 (GMT)
Quoting StormW: Good research, Levi! Thanks Storm :) Member Since: 24.11.2005 Posts: 593 Comments: 25604

1089. weathermanwannabe 22. maaliskuuta 2010 klo 17:30 (GMT)
Quoting FloridaTigers: When should we see this current upswing in Atlantic cyclone activity begin to decline? Historically around a 20-30 year cycle from when this active period started around 1995; problem is it doesn't just "shut off" so we would need to see a few consecutive years of below average activity to officially declare that the current active cycle has come to an end me thinks. Member Since: 8.08.2006 Posts: 0 Comments: 6857

1090. Michfan 22. maaliskuuta 2010 klo 17:33 (GMT)
Always love Levis research. Gives a great perspective into the data behind the predictions. Member Since: 7.09.2007 Posts: 0 Comments: 1554

1091. weathermanwannabe 22. maaliskuuta 2010 klo 17:33 (GMT)
My bad if I was off by 10 years (I thought it was 20-30 versus 30 to 40)........... :) Member Since: 8.08.2006 Posts: 0 Comments: 6857

1092. weathermanwannabe 22. maaliskuuta 2010 klo 17:38 (GMT)
Posted by: JeffMasters, 2:39 PM EST on December 19, 2005 Before we can discuss the possible influence of global warming on hurricanes, we need to set the stage by talking about this natural cycle of hurricane activity we hear so much about. The Atlantic Multidecadal Oscillation (AMO) is a cyclic variation in the large-scale atmospheric flow and ocean currents in the North Atlantic Ocean that combine to alternately increase and decrease Atlantic sea surface temperatures (SSTs). As its name indicates, the AMO is "multidecadal"--meaning it operates on a time scale of multiple decades. The cool and warm phases last for 25-45 years at a time, with a difference of about 1?F (0.6?C) between extremes. These changes are natural. Analysis of tree rings, fossil coral, and sediments has shown that the AMO has been around at least 300 years, and probably much longer. What has the AMO done in recent years? As seen in Figure 1, the AMO has been though about two complete cycles since detailed measurements of the Atlantic began in the mid-1800s. A cool phase lasted 25 years from 1901-1925, a 44-year long warm phase from 1926-1969, and a 25-year long cool phase from 1970-1994. A new warm phase began in 1995, and the AMO index values since 2001 have been the highest on record. This has resulted in sea surface temperatures over the prime hurricane breeding grounds of the tropical North Atlantic being the highest on record, as well. The AMO index in 2004 was about the same as in 2003, but 2005 has seen about a 10% drop from 2004's level. Member Since: 8.08.2006 Posts: 0 Comments: 6857

1093. wunderkidcayman 22. maaliskuuta 2010 klo 17:42 (GMT)
Hi guys we had a light shower not to long ago we need more Member Since: 13.06.2009 Posts: 2 Comments: 5997

1094. Patrap 22. maaliskuuta 2010 klo 17:57 (GMT)
AIR Estimates Windstorm Xynthia Insured Losses at $2 to $4.1 Billion Catastrophe risk modeling firm AIR Worldwide has estimated that insured losses in France, Belgium, Germany, and Netherlands from winter storm Xynthia will be between €1.5 billion and €3 billion [$2 to $4.1 billion]. The storm struck the Atlantic coast of Western Europe on Saturday February 27th, in the northern provinces of Spain and Portugal. It then moved northeast over the Biscayan Sea into central France before losing intensity on its path through Germany and eventually dissipating over the Baltic Sea. [See IJ web site - http://www.insurancejournal.com/news/international/2010/03/01/107736.htm ] "Xynthia brought with it a potent combination of hurricane-force gusts and torrential rains, causing property damage across parts of Spain, France, Belgium, and Germany," explained Dr. Peter Dailey, director of atmospheric science at AIR Worldwide. "Within the last two weeks, a cluster of three winter storms—Undine, Wera and Xynthia—moved into Europe only a few days apart, and each of them tracked along a strong southerly jet stream across a region north of the Canary Islands," he added. "Among the three storms, meteorological conditions were most favorable for Xynthia's development because the storm formed farther south than the other two and therefore was able to tap into an unusually warm and moist air mass. Enhancing the amount of available moisture for Xynthia was the presence of unseasonably warm sea surface temperatures of 14 degrees Celsius [57.2°F]." Member Since: 3.07.2005 Posts: 377 Comments: 112955

1095. Bordonaro 22. maaliskuuta 2010 klo 17:59 (GMT)
Much better weather today for North Central TX, after a 47F high temperature on Sunday, March 21st, with NW winds of 25-40MPH: Member Since: 25.08.2009 Posts: 20 Comments: 6785

1096. Patrap 22. maaliskuuta 2010 klo 17:59 (GMT)
Member Since: 3.07.2005 Posts: 377 Comments: 112955

1097. weathermanwannabe 22. maaliskuuta 2010 klo 18:03 (GMT)
1096. Patrap 1:59 PM EDT on March 22, 2010 Thanks for the reminder..........Not looking good this year so far just based upon the location of the current warm pool right across the CV season MDR........ Member Since: 8.08.2006 Posts: 0 Comments: 6857

1098. Bordonaro 22. maaliskuuta 2010 klo 18:04 (GMT)
MESOSCALE DISCUSSION 0205 NWS STORM PREDICTION CENTER NORMAN OK 1144 AM CDT MON MAR 22 2010 AREAS AFFECTED...PORTIONS OF ERN OH...NRN WV...NRN AND CENTRAL VA...WRN MD...AND SWRN/S CENTRAL PA CONCERNING...SEVERE POTENTIAL...WATCH UNLIKELY VALID 221644Z - 221845Z INCREASING CONVECTION IS ANTICIPATED ACROSS PORTIONS OF THE UPPER OH VALLEY/APPALACHIANS REGION OVER THE NEXT COUPLE OF HOURS. WHILE MARGINAL HAIL AND GUSTY WINDS WILL BE LIKELY WITH A FEW STRONGER CELLS...ATTM EXPECT ANY SEVERE THREAT TO REMAIN INSUFFICIENT TO REQUIRE A WW. LATEST VISIBLE IMAGERY SHOWS A PERSISTENT AREA OF CLEARING ACROSS THE UPPER OH VALLEY AND INTO SWRN PA/WV AND PORTIONS OF WRN VA...WHERE SURFACE TEMPERATURES CONTINUE TO INCREASE THROUGH THE 60S. THIS COMBINED WITH DEWPOINTS GENERALLY IN THE 50S WITHIN A TRIANGULAR-SHAPED WARM SECTOR RESIDING ACROSS THE MID-ATLANTIC REGION IS RESULTING IN A SLOWLY DESTABILIZING AIRMASS. WITH MODEST HEATING/DESTABILIZATION TO CONTINUE THROUGH THE AFTERNOON...EXPECT A SLOW INCREASE IN CONVECTIVE COVERAGE/INTENSITY NEAR AND AHEAD OF THE COLD FRONT -- NOW MOVING NEWD ACROSS WV/CENTRAL VA/NERN NC. THOUGH FAVORABLE SHEAR -- VEERING AND INCREASING WITH HEIGHT THROUGH THE LOWER AND MID TROPOSPHERE -- SHOULD HELP TO SUSTAIN ISOLATED/RELATIVELY VIGOROUS STORMS THROUGH THE AFTERNOON...LIMITED INSTABILITY SUGGESTS THAT SEVERE POTENTIAL WILL LIKELY REMAIN LIMITED -- AND THEN DIMINISH QUICKLY BY EARLY EVENING. ..GOSS.. 03/22/2010 Member Since: 25.08.2009 Posts: 20 Comments: 6785

1099. Patrap 22. maaliskuuta 2010 klo 18:08 (GMT)
Quoting weathermanwannabe: 1096. Patrap 1:59 PM EDT on March 22, 2010 Thanks for the reminder..........Not looking good this year so far just based upon the location of the current warm pool right across the CV season MDR........ Found some graphics from NOAA and thought they would show well the situ Member Since: 3.07.2005 Posts: 377 Comments: 112955

1101. chucky7777 22. maaliskuuta 2010 klo 18:10 (GMT)
I had no idea that Europe had names for the winter storms over there, not until Xynthia, it caused damage to a wide area . France has some outdated seawalls in areas along it's coast and Xynthia exposed the weaknesses, interesting,ok i'm back into lurk mode....... Member Since: 19.10.2005 Posts: 0 Comments: 174

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