Scientific Forecaster Discussion

NWS Discussion
			
				

Area forecast discussion 
National Weather Service Paducah Kentucky 
651 PM CDT Wednesday may 22 2013 


Update... 
issued at 650 PM CDT Wednesday may 22 2013 


The aviation section has been updated for the 00z taf issuance. 


&& 


Short term...(this evening through Friday night) 
issued at 239 PM CDT Wednesday may 22 2013 


500 mb low over northern Iowa will open up and move east into the Great Lakes 
region by midday Thursday. Will linger a small chance of weak 
convection through the afternoon and evening hours across the area. 
Will carry small chances of showers Thursday as the mean trough axis 
moves across the area...early in the day. Dry weather returns for 
Thursday night through Friday night as a decent area of high 
pressure builds southeast and across the four state area. 


Long term...(saturday through wednesday) 
issued at 239 PM CDT Wednesday may 22 2013 


Models still differ for the late weekend/early work week weather 
system. European model (ecmwf) and GFS both Show Low pressure off the northeast 
coast at 00z Sunday...with a front extending west to low pressure 
over the plains states. GFS has the plains low farther north than 
the GFS...thus keeping precipitation chances farther north and out of the 
the pah forecast area through most of the extended. European model (ecmwf) shows on 
and off chances of precipitation through the same time period. Both 
models are now remaining fairly consistent with their solutions. 
Gem seems to be a good blend of the two...and has been trending a 
bit more toward the farther south European model (ecmwf). Will lean toward the Gem 
compromise...which leads to including some slight to low chance 
probability of precipitation for our west and northwest counties Saturday night into 
Sunday...and across the entire forecast area Sunday night into Monday and 
then again on Tuesday. Quantitative precipitation forecast amounts should not be too significant 
due to the scattered nature of any convection. European model (ecmwf) tries to 
continue to hang on to the precipitation even into Wednesday...but both 
GFS and European model (ecmwf) build an upper level ridge over the south 
central/southeast u... went with a dry forecast for now. 


Temperatures will continue to be a little cooler than seasonal 
averages Saturday into Saturday night...then moderating to near 
seasonal on Sunday. A return to more southerly flow Saturday and 
especially into Sunday will lead Toa gradual warm up and slightly 
warmer than average temperatures by Tuesday into Wednesday. 


&& 


Aviation... 
issued at 650 PM CDT Wednesday may 22 2013 


One isolated shower will flirt with kevv in the next half hour. 
Otherwise the forecast will be dry through Thursday morning. A few 
west southwesterly gusts will be possible throughout the area 
until sunset. Satellite imagery and the latest computer 
guidance suggest that cloud cover should decrease through the night. 


The final middle/upper level impulse will surge southeast through the 
region Thursday. This will bring a surge of surface high 
pressure...with increasingly gusty northwest winds from middle- 
morning through the afternoon. Scattered showers will be possible 
at kevv and kowb during the afternoon. Not certain on coverage or 
intensity...so just inserted a vcsh both sites through the 
afternoon. 


Cannot rule out a MVFR ceiling at kevv/kowb in the afternoon...but 
definitely should see low VFR ceilings...possibly as far south and 
west as kcgi and kpah. 


&& 


Pah watches/warnings/advisories... 
Illinois...none. 
MO...none. 
In...none. 
Kentucky...none. 
&& 


$$ 


Update...drs 
short term...cn 
long term...rst 
aviation...drs