Area Forecast Discussion
Issued by NWS Wilmington, OH

Home | Current Version | Previous Version | Text Only | Print | Product List | Glossary Off
Versions: 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50

FXUS61 KILN 260753

Area Forecast Discussion
National Weather Service Wilmington OH
353 AM EDT Sat May 26 2018

An upper level disturbance will move across the region today
bringing shower and thunderstorm chances back to the Ohio
Valley. The best chance of rain today will be in the afternoon
and evening hours. A few additional storms will be possible
Sunday and Monday with warmer weather forecast.


An upper level disturbance is currently approaching the area
from the west along with weak showers. This afternoon weak PVA
will be overhead as well as a very moist airmass. On both the
GFS and NAM, PWATs are around 1.70" (approaching max values for
this time of year) with forecast soundings showing
destabilization. The only area of slight concern is on GFS
forecast soundings with widespread high and mid clouds forecast.
This could hinder daytime destabilization somewhat and
therefore hinder thunderstorm coverage. The latest runs of the
ARW, NMM, and NSSL show pretty good coverage, but do hint at
more restrictive spatial coverage of storms. The HRRR on the
other hand shows very good coverage. Overall, more places than
not will likely observe rain today. Shear profiles this
afternoon are extremely weak, meaning the severe potential for
today will be very low.


This evening showers and thunderstorms will be likely across the
area and slowly decrease in coverage as daytime heating is lost.
This evening the shortwave will also exit the area with weak
subsidence and drier air moving in behind. PWATs Sunday morning
will continue to fall and be below 1.00" across our far
northwestern zones. The exception will be across our
southeastern zones were moist air will try to hold on. At the
same time Sunday, mid-level ridging will begin to take hold
across the central United States with 850 mb temperatures
responding accordingly across our western zones. Both the ECMWF
and GFS are in fairly good agreement with 850 mb temperatures
rising to around 18 degrees C across our western zones. These
warm low level thermal profiles with a potentially wet ground
will make for a complicated Sunday high temperature forecast. In
general, drier soil will warm up quicker than moist soil,
meaning that the spatial distribution and intensity of todays
rainfall will likely impact Sundays high temperatures. For now,
have just raised temperatures up across the board for Sunday,
but a tighter west/ east temperature gradient will likely exist
than currently depicted.


A southwest to northeast oriented mid and upper level ridge axis
will be in place from Texas into the southern Great Lakes Sunday
night into Monday. This will be in between a tropical system lifting
slowly north toward the Gulf Coast States and an upper level low
over the Rockies. With subsidence across much of our area and a dry
airmass in place, generally expect dry conditions on Monday. The
exception may be across our far south, where slightly better
moisture and some better instabilities could lead to an isolated
afternoon shower or thunderstorm.  Highs on Monday will push into
the upper 80s to around 90 degrees.

The tropical system will continue to lift north across the Gulf
States through the day on Tuesday, eventually helping to begin to
break down the ridge across our region. This will again bring a
chance of an isolated shower or thunderstorms into southern portions
of our area through the day on Tuesday. Clouds will also be on the
increase through the day, possibly helping to keep down temperatures
a tad, with highs mostly in the mid to upper 80s.

The tropical remnants will lift north across our area Tuesday night
into Wednesday night, although there are some timing differences with
this among the models. Will therefore allow for more widespread
showers and embedded thunderstorms to overspread our area later
Tuesday night, continuing through Wednesday and possibly into
Wednesday night. Highs on Wednesday will be in the lower to possibly
mid 80s.

Late in the week, the models differ on how exactly to phase the
tropical remnants into a trough moving across the Great Lakes region.
As a result, there is quite a bit of uncertainty in the later
periods of the long term forecast. For now, will just linger some
chance pops for Thursday into Friday with highs mostly in the mid


Mostly VFR conditions are expected through the morning hours
ahead of the next approaching shortwave. High res models show
the showers and thunderstorms quickly weakening as they move
overhead this morning which makes sense as forcing is very weak.

During the afternoon today forecast soundings on both the NAM
and GFS quickly destabilize as PWATs rise to around 1.7". Shear
values are extremely weak this afternoon though which means that
storms will likely quickly pop up and then collapse. So
prevailing multi-hour thunder or precipitation is probably
unlikely today at any given spot, but instead showers and
thunderstorms will likely be transient as storms should quickly
form and then collapse. In any heavier thunderstorms IFR
restrictions in visibilities will be likely. This evening
showers and thunderstorms will decrease in coverage as daytime
heating is lost.

OUTLOOK...Afternoon and evening thunderstorms are possible
Sunday and then again Wednesday.




NEAR TERM...Haines
AVIATION...Haines is the U.S. government's official web portal to all federal, state and local government web resources and services.