419 
fxus61 kcle 191728 
afdcle 


Area forecast discussion 
National Weather Service Cleveland Ohio 
128 PM EDT Friday Mar 19 2010 


Synopsis... 
an area of high pressure centered over the Southern Plains will 
provide another day and a half of warm and dry weather before moving 
off the southeast coast. A cold front will sag south across the 
Great Lakes on Saturday. Low pressure is expected to develop on the 
front over the Tennessee Valley on Sunday and move east by Monday. 


&& 


Near term /until 6 PM this evening/... 
surface high and ridge aloft now centered well to the south over the 
Gulf Coast states and we will see varying amounts of high clouds 
slide over the top of the ridge today. Nonetheless...it will still 
be quite the Spring day...the day before Spring officially starts... 
with high temperatures again in the 60s and a fair amount of 
sunshine. MOS maximum temperature guidance has been running too cool and 
it looks too cool again based on upstream temperatures and forecast 
will be a category or two above guidance. Lake breeze will be 
confined to the immediate Lakeshore northeast of Cleveland where the 
southwest flow will come onshore this afternoon. 


&& 


Short term /6 PM this evening through Monday night/... 
pressure gradient is somewhat less tonight and despite the high 
clouds there is a better chance for a little radiational cooling. 
Min temperature forecast will be close to guidance...generally in 
the lower 40s. 


Models have been trending faster with the next cold front sagging 
across the area from northwest to southeast on Saturday. These types 
of fronts typically have Post frontal precipitation so I think most 
of the showers/sprinkles will hold off until later in the day across 
the Lakeshore counties and across Northwest Ohio. Temperatures will 
be cooler after frontal passage especially near the Lakeshore as the 
wind comes off the water. 


A surface low is expected to develop on the front and should develop 
well to the south as the upper low cuts off and rolls across the 
southern states. This will keep US on the cool side of the system 
but the air mass will be cooled mainly by clouds/rain and seemingly 
will not tap any true cold air. Nonetheless...Sunday will be cooler 
especially compared to recent days and especially near Lake Erie 
with a flow off the water. Some of the guidance is printing out 
freezing rain Saturday night/Sunday morning but with the clouds and 
showers/sprinkles and lack of true cold air do not think we will get 
quite that cold. 


Temperatures will also be tricky on Sunday. Some of the guidance is 
showing a light southeast flow which could allow the warmer air back 
into places like Millersburg and Canton and Youngstown. This would 
especially be likely if there was not much rain. Will keep a nice 
maximum temperature gradient on Sunday with 40s near Lake Erie and Northwest 
Ohio and near 60 across the southeast part of the forecast area. 


GFS looks too far north with the surface low by Monday morning 
although I expect an inverted trough into the upper Ohio Valley. 
Showers will take a while to shift east and cool northeast flow will 
continue. 


Should be able to warm right back up after we can shake the clouds 
by Tuesday. 


&& 


Long term /Tuesday through Thursday/... 
we should be able to warm right back up to near normal after we 
can shake the clouds on Tuesday except of course near Lake Erie. 


Timing of the systems toward the end of the forecast period in 
doubt. By 12z Wednesday the GFS moves a low pressure system 
across the Central Lakes dragging a cold front across the area 
with more high pressure over the area by 12z Thursday. The European model (ecmwf) 
on the other hand is much slower. It has the low moving across 
Lake Superior with a secondary wave developing along the frontal 
boundary. This slows the frontal passage until Thursday. At this 
point used the slower European model (ecmwf) solution for the forecast. 


&& 


Aviation /18z Friday through Tuesday/... 
VFR weather will continue through at least the first half of the 
taf period with high pressure still in control of the areas 
weather. A cold front will begin to drop south across the area 
late tonight and Saturday morning. Expect ceilings to lower to MVFR a 
few hours after the front moves through. There is a chance of rain 
showers late in period but felt that the probability was fairly 
low and didn't mention any precipitation in the tafs for this forecast. 


Outlook...expect non VFR conditions with occasional rain showers 
on and off from Saturday afternoon through Monday. VFR Tuesday. 


&& 


Marine... 
southwesterly flow will continue today...but change is on the way. 
Winds turn to the north through northeast Saturday as a cold front 
pushes across the lake. Winds will remain that direction through 
the weekend as the front stalls south of the lake. Winds pick up 
Monday as a low pressure system moves across southern Ohio. Right 
now expect winds to increase to 15 to 25 knots Monday. Winds begin 
to lighten up on Tuesday as high pressure builds over the area. 


&& 


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


&& 


$$ 
Synopsis...kosarik 
near term...kosarik 
short term...kosarik 
long term...djb/kosarik 
aviation...randel 
marine...djb