Scientific Forecaster Discussion

NWS Discussion
			
				

Area forecast discussion...updated 
National Weather Service Jackson Kentucky 
845 PM EDT Thursday may 23 2013 


Update... 
issued at 840 PM EDT Thursday may 23 2013 


00z surface analysis shows a secondary cold front crossing into Kentucky 
from a low pressure area moving into New England. A large area of 
cool high pressure descending from the upper Midwest follows this 
front. Along the boundary to our northwest...there is a broken line 
of light showers at the moment. The convection from the afternoon and 
early evening has departed far eastern parts of the area taking any 
risk for thunderstorms along with it. As such...have updated the 
forecast to address this and also fine tune the timing of the precipitation 
threat with the next boundary. Did also minimize the rain chances in 
the east for the next several hours before they pick up again with 
the approach of the front. Finally...matched up the T and dew point grids 
for the latest observation and trends. Updates have been sent to the ndfd and 
web servers along with a fresh set of zones and severe weather potential statement. 


&& 


Short term...(this evening through Friday night) 
issued at 223 PM EDT Thursday may 23 2013 


The models are in pretty good agreement with the timing of the systems 
moving across the area. A weak cold front is currently moving across 
the area. It has produced scattered showers across the Coal fields 
and there has also been a couple of thunderstorms mainly near the WV 
border. There is a front with cooler air behind it which will be moving 
across the area this evening. It will also bring some scattered 
showers to the area tonight. One concern is how cold will it get on 
Friday night as the clouds move out of the area and the winds stay 
light. Expecting to some some patchy valley frost that 
evening...however no hard freezes. 


Long term...(saturday through thursday) 
issued at 241 PM EDT Thursday may 23 2013 


Models are in decent agreement through the remainder of the 
weekend...but start to diverge by early next week with confidence in 
the forecast much less from Monday Onward. The period will start with 
surface high centered over the area...providing tranquil conditions. 
By late in the weekend...a warm front will develop over the Ohio 
Valley. The GFS is much more aggressive with the warm front lifting to 
the northeast...while the European model (ecmwf) is much slower. A compromise of the 
two would keep the boundary in our vicinity through 
midweek...supporting some isolated showers and thunderstorms across a 
portion of the area each day. This may be confined to the afternoon 
and evening each day. Otherwise...no significant pieces of energy 
rotating through the area...so it looks like isolated activity may be 
the best we do into next week. Of course with the models in 
disagreement on evolution...things could change warranting a period 
of higher probability of precipitation. After cooler weather this weekend...a gradual warming 
trend is anticipated into next week as the warm front lifts across 
the area. 


&& 


Aviation...(for the 00z tafs through 00z Friday evening) 
issued at 845 PM EDT Thursday may 23 2013 


Another round of scattered showers is expected to pass through east 
Kentucky late tonight as a secondary cold front drops through the 
area. From this...a bout of lower clouds and reduced visible...down to 
MVFR for a time...is anticipated. Conditions will improve early 
Friday as high pressure clears out the lower clouds and yields VFR 
conditions from middle morning on. Breezy northwest winds of 10 to 20 
kts will settle a bit overnight before resuming from the north during 
the day Friday. 


&& 


Jkl watches/warnings/advisories... 
none. 
&& 


$$ 


Update...greif 
short term...jj 
long term...kas 
aviation...greif