Scientific Forecaster Discussion
Area forecast discussion
National Weather Service Wilmington Ohio
1024 am EDT Wednesday Jul 23 2014
a cold front will push showers and thunderstorms across the area
today. High pressure will bring cooler and less humid conditions
for Thursday. Disturbances in the upper atmosphere could result in
additional thunderstorms on Friday and Saturday.
Near term /until 6 PM this evening/...
area of convection from overnight continues to weaken as it pushes
east of I-71. Additional thunderstorms have developed back over
central Indiana however. This convection should work eastward into the
Whitewater valley and through the cincy tri-state region.
For this afternoon...it is still looking like thunderstorms will
redevelop southeast of I-71 as the instability builds during the heat of
the afternoon. We could see an isolated strong to severe storm.
Temperature forecast will be tricky for this afternoon. Where the
convection is the heaviest...temperatures will be held down
more....but just a little sunshine will cause temperatures to
soar. Tinkered with the highs a little. The general trend is the
upper 70s in the northwest...ramping up to the upper 80s in the southeast.
Short term /6 PM this evening through Thursday night/...
front will be moving south of the Ohio River tonight...bringing an
end to showers and thunderstorms. As high pressure moves in from
the north...sky cover will decrease and temperatures will cool to
the 50s and 60s for lows.
Surface high pressure traveling on a northwest upper flow will
cross the region on Thursday. A cool and dry airmass will
rule...with highs in the 70s expected.
For Friday...dry weather is forecast early in the day as the
surface high continues its southeastward movement. On Friday
afternoon...a short wave trough may provide enough lift and
increasing instability to bring a few showers and thunderstorms
to northwest counties. Temperatures on Friday will be boosted a
bit by warm advection...giving highs near 80
Long term /Friday through Tuesday/...
an upper level disturbance embedded in northwesterly flow
approaches our region Friday night. Models have accelerated the
arrival of this disturbance...yet still vary by several hours on
their forecast arrival of precipitation on Saturday. Added low
chance probability of precipitation early Saturday morning with probability of precipitation ramping up into the
day Saturday based on the faster trend. Kept only chance probability of precipitation on
Saturday due to timing and coverage uncertainties for
precipitation on Saturday. Temperatures under the high on Friday
will remain a few degrees below normal. Once the high shifts to
our southeast...a rebound to near normal temperatures can be
expected for Saturday.
On Sunday...a unseasonably deep trough is expected to dig
southeastward across the middle west and into the Ohio Valley. Low
pressure downstream of this trough will drag a cold front across our
area. The CMC and GFS are in fairly good agreement on bringing
enhanced chances for precipitation to our area on Sunday ahead of
this front...with the cold front crossing our area at some point
late Sunday. Best chances for precipitation appear to be during the
day Sunday in the warm sector...with cooler air moving into the
region by Monday. The trough is forecast to remain in the region
through the early parts of next week. Models vary on how much
moisture lingers behind the front. Am forecasting mainly low chance
diurnally driven showers and isolated thunderstorms in the cold
sector. This high amplitude trough will bring another round of well
below normal temperatures to the Ohio Valley early next week...with
current indications being that highs may only reach the lower 70s on
Monday and possibly again on Tuesday.
Aviation /14z Wednesday through Sunday/...
a strong cold front will drop down from the northwest today and
push across the taf sites this morning into early afternoon. Latest
radar mosaic shows convection ahead of this front overspreading
the northwest half of Ohio and the northern taf sites. These storms will
continue to move southeast overspreading all taf sites early this morning.
Have prevailing showers and thunderstorms at all taf sites this
morning with MVFR visibilities and VFR ceilings. A brief period of IFR visibilities
in heavier rain shower is not out of the question. Thunderstorm
converge expected to re-develop along the front as moderate instability
develops this afternoon. The best chance for this re-development looks
to be along and southeast of I-71 corridor. Have a mention of thunderstorms in the vicinity to
account for this chance later today as the frontal passage takes place.
Expect winds to shift to the northwest and then NE with VFR
conditions this evening.
Outlook...thunderstorms possible Saturday and Sunday.