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fxus63 kapx 180419 
afdapx 


Area forecast discussion 
National Weather Service Gaylord Michigan 
1217 am EDT Thursday Mar 18 2010 


Synopsis.../issued at 355 PM/ 


High pressure will continue to dominate the weather over the 
Great Lakes through Thursday...keeping warm and dry conditions on 
tap through this time. Friday may be another warm one. However...a 
developing area of low pressure will be approaching...bringing 
cooler temperatures...a chance for rain and possibly even snow for 
the weekend. There is still a fair amount of uncertainty with this 
storm track and strength of this low...so to what extent the 
precipitation will line up with the intrusion of cold air is a bit 
unclear. 


Berger 


&& 


Short term.../issued at 1018 PM/...tonight 


High pressure at the surface and aloft will remain in control 
overnight. This is expected to lead to mostly clear skies with 
only a bit of cirrus topping the ridge and moving into mainly 
eastern upper. Temperatures have been a bit tricky this evening 
with the extremely dry airmass remaining in place. Some spots have 
rapidly fallen off into the middle 30s already after daytime highs 
in the middle 60s. Temperatures are expected to level off 
overnight as the pressure gradient tightens up a bit out ahead of 
a weak front/trough. Did lower mins by a few degrees to account for 
current trends...and expect lows ranging from the upper 20s to middle 
30s. 


Sullivan 


&& 


Long term.../issued at 355 PM/...Thursday and beyond 


Main focus on the extended part of the forecast will focus on the 
upcoming weekend...as the weather turns more active. Temperatures 
will turn much colder heading into the weekend...with a mixture of 
snow and rain expected throughout the first half of the 
weekend...then another shot for snow early next week. 


Thursday into Friday...as a middle level wave works eastward across 
central Canada...northern Michigan will remain under the influence 
of weak middle level ridging...providing a continuation of tranquil 
weather conditions through weeks end. Only concern will be the 
encroachment of some high/middle level clouds which may act to keep 
temperatures 5 to 10 degrees cooler on Friday. However...as far as 
Thursday GOES...likely our warmest day of the week with highs easily 
climbing to the 60 degree plateau...with some middle/upper 60s possible 
in downslope flow areas of northeast lower Michigan. 


Friday night...middle level wave across Canada will skirt by the area 
to the north...dragging a baroclinic zone into northern Michigan. 
Meanwhile...southern stream wave will act to develop a surface low 
in the Ohio Valley. A band of fgen precipitation will likely form on 
the northwest side of this system...although quite a bit of 
uncertainty still remains on the exact placement of this band of 
precipitation. As of right now...it appears by late Friday 
night...light precipitation will break out across northern lower 
Michigan...perhaps keeping eastern upper on the drier side. 
Regardless...only change was to increase probability of precipitation for the second half of 
Friday night. At least early on...the precipitation will be 
primarily rain. 


Saturday/Saturday night...light to moderate precipitation will 
continue across northern lower Michigan during the day...eventually 
drifting south and east as the area of low pressure to our southeast 
begins to lift away from the area. As it appears right now...models 
may be over doing the cold air a touch and feelings are that we will 
likely see more rain than snow through much of Saturday. I think we 
may start to change over to snow on the northern edges of the band 
of precipitation as the colder starts filtering in Saturday evening. 
However...snow accumulations at this Point May not be all that 
impressive considering a good chunk of the event may be a mix of 
rain and snow. However...perhaps an inch of accumulation may be 
possible by early Sunday morning. Conditions certainly turning much 
colder as the cold air begins to funnel into northern Michigan. 


Sunday...has actually been trending towards a drier day...as we wait 
for another weak clipper system dropping into the area from the 
northern plains. Have trended probability of precipitation downward...but with a few more 
forecast cycles...these probability of precipitation may be dropped altogether. 
However...with so much uncertainty with the weekend...opting to keep 
some small chances for snow. 


Sunday night Onward...a clipper system will drop across northern 
Michigan late in the weekend...producing a better chance for some 
light to moderate snowfall. At this point...system will be a quick 
hitter...so snowfall amounts will remain on the lighter side 
(although certainly more than we have seen in quite some time). As 
the system departs Monday...we may actually get cold enough air into 
the Great Lakes for a brief period of lake effect snow. However...by 
Monday night into Tuesday...we already start to warm as as upper 
level ridging builds into the Great Lakes. 


Kas 


&& 


Marine.../issued at 355 PM/ 


Winds and waves expected to remain below Small Craft Advisory criteria tonight 
through the forecast period...as high pressure lingers over the 
central parts of the country and Great Lakes region. This pattern 
will generate dry conds into Friday...over the Northern Lake nearshore 
waters. A weak frontal boundary slowly dropping across Ontario 
Thursday...will generate southwesterly winds through the nearshore 
period. 


Swr 


&& 


Aviation.../issued at 1214 am/...valid for 06z tafs 


High pressure will continue to generate IFR ceilings/visibilities over northern Michigan taf 
sites into Thursday evening. Will continue to include low level wind shear to taf 
sites early this morning...as middle level winds increase above 
developing low level inversion. 


Ajs 


&& 


Apx watches/warnings/advisories... 
Michigan...none. 
Lm...none. 
LH...none. 
Ls...none. 


&& 


$$