908 
fxus61 kcle 171927 
afdcle 


Area forecast discussion 
National Weather Service Cleveland Ohio 
327 PM EDT Wednesday Mar 17 2010 


Synopsis... 
high pressure ridge across the region will weaken by Thursday 
night as a weak trough brushes Northern Ohio. A cold front will 
approach the area for the weekend. 


&& 


Near term /until 6 am Thursday morning/... 
mostly clear skies and light winds with below normal temperatures. 
Went close to cooler MOS guidance for the lows. 


&& 


Short term /6 am Thursday morning through Saturday night/... 
some cirrus for Thursday but still should be mostly sunny. Should 
be an onshore wind again but the synoptic flow will be more 
westerly so the impact except east of cle will not be as extreme 
as the last few days. 


A slow increase in clouds Friday with plenty of clouds for 
Saturday. If the European model (ecmwf) model is correct temperatures will cool 
down Saturday afternoon...if the other models are correct it will 
be warmer. The threat of showers will try to hold off until 
Saturday evening and night. Still playing this way with the 
forecast but this will have to be watched. 


&& 


Long term /Sunday through Tuesday/... 
the cold front will move through the state Sunday with rain showers. 
Some model differences on how quickly the cold air will move in. If 
the GFS/Gem is right snow showers could be occurring by Sunday 
afternoon. At this time with some question will go with the European model (ecmwf) 
which brings in the colder air a little slower. A dry slot may 
occur after the frontal passage and then some wrap around moisture 
as a surface trough moves through for a threat of snow showers. 
With the model differences didnt change things too much from the 
previous forecast until the model change becomes consistent. High 
pressure will begin to build in by Monday night. The high will 
move east of the region by late Tuesday and temperatures will 
begin to rebound quickly in the southerly flow. A weather system 
will be heading toward the area for the later part of the week. At 
this time will keep Wednesday night dry. 


&& 


Aviation /19z Wednesday through Monday/... 
VFR weather continues as high pressure ridge will remain across the 
area into Thursday. Some cirrus clouds will be around. The air mass 
is dry enough that no fog expected at taf sites...however...some 
isolated 5sm br could occur around sunrise. A northerly flow will 
occur this afternoon with a lake breeze developing Thursday afternoon. 


Outlook...Thursday through Saturday generally VFR with isolated MVFR 
fog possible each morning. Non VFR Sunday and Sunday night with 
front in the area. Improving conditions Monday. 


&& 


Marine... 
tranquil conditions are expected until the weekend as high pressure 
over the Mississippi Valley slowly builds east into the Tennessee 
Valley while low pressure moves across the northern lakes. Surface 
pressure gradient gradually increase winds on Friday. 


Rather uncertain forecast for the weekend as GFS and European model (ecmwf) continue 
to be quite different with the treatment of a short wave that is 
expected to move out of the Southern Plains and into the region 
Sunday and Monday. The European model (ecmwf) is much slower in the progression of 
the system since its associated upper level support cuts off over 
the MS/Tennessee valleys. The GFS keeps an open wave and sweeps it off the 
East Coast. We will trend toward the Euro and slow the frontal 
passage and keep winds lighter until Monday. 


&& 


Cle watches/warnings/advisories... 
Ohio...none. 
PA...none. 
Marine...none. 


&& 


$$ 
Synopsis...kieltyka 
near term...kieltyka 
short term...kieltyka 
long term...kieltyka 
aviation...kieltyka 
marine...relatively