Area forecast discussion
National Weather Service Cleveland Ohio
738 PM EDT sun may 19 2013
Synopsis...
above normal temperatures will continue the next few days as a ridge
of high pressure builds aloft. Meanwhile...an area of low pressure
over the northern plains will slowly progress eastward across the
Great Lakes region through middle week. The airmass will become
increasingly moist and unstable as this feature approaches.
&&
Near term /until 6 am Monday morning/...
update...minor adjustment to hourly temperatures were made. Also
decreased clouds for the evening and removed probability of precipitation as satellite and
radar shows diurnal trends of becoming more stable.
Original...scattered showers have developed beneath an enhanced
cumulus field across north central Ohio from roughly Marion to
Sandusky. Storm Prediction Center analysis shows 1000-1500 j/kg of surface based cape
with favorable low level lapse rates of 7.5 c/km. Lightning has
been extremely isolated thus far as showers struggle to grow with
warm air in the middle-levels beneath the strong upper level ridge
aloft. Some of the hi-res models indicate the showers will expand
eastward through early evening and will continue to carry an
isolated mention of showers/thunderstorms through about 00z. With
the loss of daytime heating...expect to see most of the clouds
clear out before increasing from the west as moisture advection
ramps up late. Added some patchy fog into the western counties as
well with dewpoints in the low 60s overnight. With more moisture
around tonight...expect mins to be a little warmer than last night
with more locations bottoming out in the low 60s.
&&
Short term /6 am Monday morning through Wednesday night/...
challenge through the short term forecast will be trying to time
showers and thunderstorms as the plains upper low slowly approaches
from the west. Low level Theta-E ridge expands north over the area
on Monday and have included a chance of sprinkles in the morning in
Northwest Ohio. Otherwise expecting the airmass to largely be capped as
700mb temperatures increase to 8c. The warming trend will continue
with increasing southwesterly flow and highs will reach the upper
80s in Northwest Ohio...tapering to the lower 80s in northwest PA.
Chances for showers and thunderstorms start to increase on Monday
night as energy tries to round the ridge...with probability of precipitation up to 50-60
percent by Tuesday afternoon. The ridge axis will be east of the
area by that time and models show shortwave energy ejecting out of
the trough across Northwest Ohio. The airmass will become increasingly
moist and unstable as dewpoints make a push towards the upper 60s.
The Storm Prediction Center does include the Toledo area in a slight
risk for severe storms for late Tuesday.
Upper level support for showers and thunderstorms increases into
Wednesday as the trough pivots eastward. Would expect greater
coverage of storms and will have to monitor for some to be strong to
severe again. Increasing cloud cover and showers will knock highs
back down towards the lower 80s.
Overnight lows will be mild through the first part of the week with
mins in the middle to upper 60s.
&&
Long term /Thursday through Sunday/...
a cold front will move across the region Thursday. The GFS
indicates a short wave and an area of moisture just behind the front
that will rotate across the region Thursday night into Friday. The
forecast will contain likely probability of precipitation for Thursday with chance probability of precipitation for
Thursday night. I will keep a slight chance of showers for the
early part of the day on Friday. High pressure will build over the
forecast area Friday afternoon and remain for Saturday and Sunday.
&&
Aviation /00z Monday through Friday/...
Lake breeze to relax/retreat this evening. Otherwise a light
south-southeast flow can be expected overnight. With the
increased moisture present now...dewpoints up 10-15 degrees since
yesterday evening...area may get a little late night/early
morning MVFR br develop. Have continued that in the forecast. Much
of the same for Monday...afternoon cumulus to develop at or around 4k
feet. Winds more southerly Monday...and lake breeze may just be
confined to Erie...halting just north of cle.
Outlook...non VFR probable in showers/thunderstorms Monday
evening through Thursday and also in early morning br.
&&
Marine...
local effects are dominating the winds over the lake late this
afternoon. A lake breeze has turned the nearshore winds to a
northeast direction for many locations. These northeast winds will
continue into the evening hours and eventually weaken. A light
southeast flow will return over the lake during the overnight hours.
A similar pattern to today will be observed on Monday. The flow
will begin to increase from the south and southwest Tuesday into
Wednesday as a cold front approaches the lake on Thursday.
&&
Cle watches/warnings/advisories...
Ohio...none.
PA...none.
Marine...none.
&&
$$
Synopsis...kec
near term...kec/tk
short term...kec
long term...Garnet
aviation...oudeman
marine...Garnet
