Area forecast discussion
National Weather Service Wilmington Ohio
134 PM EDT sun may 19 2013
Synopsis...
a weak upper level disturbance will bring a chance of showers and
thunderstorms this afternoon into this evening. A warm front will
then lift north of the region tonight as a middle level ridge builds
into the region. A very warm and moist airmass will establish
itself across the area in the wake of the warm front for Monday
and Tuesday. The threat of showers and thunderstorms will increase
once again by Tuesday as the middle level ridge pushes east.
&&
Near term /through tonight/...
pesky upper level disturbance over the Ohio River valley will push
slowly southeast through this evening as a middle level ridge builds in
behind it later tonight. The proximity of this feature along with
daytime heating will allow showers and thunderstorms to pop once
again. Rap NAM and GFS are in good agreement in terms of quantitative precipitation forecast around
a tenth of an inch over the eastern part of the County Warning Area while the
European model (ecmwf) shows about half that amount. Coverage should be less than
yesterday with the highest chances expected across our southeast.
Any lingering showers and storms this evening should dissipate as
middle level ridge builds into the region. However...models continue
to indicate that an implied warm front will lift north across the
region late tonight. At this time will keep the forecast
dry...although there are some signals that an isolated shower or
storm could pop with its passage. Highs today will range from the
lower to middle 80s. Lows tonight will range from the lower to middle
60s.
&&
Short term /Monday through Wednesday night/...
middle level ridging on Monday should give our area a reprieve from
shower and thunderstorm activity. A very warm and moist airmass
will establish itself across the area in the wake of the warm front.
Thus...under partly to mostly sunny skies...temperatures should
warm into the upper 80s to around 90...which is much above normal
for late may. With dewpoints in the middle and upper 60s...it will
also feel quite humid.
For Monday night into Tuesday...have used a blend of the 19.00z
CMC and the 19.00z European model (ecmwf). The GFS suffers from convective feed
back which is difficult to use. During this period...middle level
ridge moves east/southeast. Our area will be located between this
ridge and a large scale middle level closed low over the northern/Central
Plains. The prospects of showers/storms during this time frame
will depend on any embedded disturbances that may eject NE around
the southeast side of the low. Have allowed probability of precipitation to incrementally
increase. Highs on Tuesday will still be very warm...ranging from
the middle 80s to around 90.
For the period Tuesday night into Wednesday night...have continued
with the aforementioned model blend. It looks like as the upper level
closed low slowly moves east/southeast toward our region...a more
bonafide shortwave and surface cold front will push through the region late
Wednesday into Thursday. Have gone with the highest probability of precipitation during
this time frame due to these features. Temperatures will show a
slow downward trend during the period with the increase in clouds
and the threat for precipitation.
&&
Long term /Thursday through Saturday/...
a middle level trough will progress slowly east across the region
through the end of the week. An associated cold front will
continue to push east on Thursday...followed by a secondary cold
front Thursday night into Friday. This will keep a chance of
thunderstorms going through the day on Thursday...with precipitation tapering
off to showers behind the secondary cold front Thursday night into
Friday. A cooler airmass will push into our area heading into the
weekend as Canadian high pressure builds in from the north later
Friday into Saturday. Highs are forecast to range from the upper
60s to the lower 70s Friday and Saturday.
&&
Aviation /18z Sunday through Thursday/...
scattered showers have developed this afternoon as a weak
disturbance enhances instability along an old frontal
boundary...mainly close to eastern sites iln cmh and lck. Some of
the showers may result in MVFR conditions. An upper ridge will
build in tonight which will help to bring showers to an end. Under
calm winds and a humid airmass...fog and br are expected to reduce
visibilities tonight. VFR conditions and southerly winds are
forecast after 12z Monday. Models predict a moderate amount of
instability for Monday...but forcing will be weak so kept showers
out of the forecast.
Outlook...thunderstorms will be possible from Tuesday through
Thursday.
&&
Iln watches/warnings/advisories...
Ohio...none.
Kentucky...none.
In...none.
&&
$$
Synopsis...Hickman
near term...coniglio/Hickman
short term...Hickman
long term...Hickman/jgl
aviation...coniglio
