896 
fxus63 kapx 231147 
afdapx 


Area forecast discussion 
National Weather Service Gaylord Michigan 
645 am EST Monday Nov 23 2009 


Synopsis.../issued at 429 am/ 


High pressure to our east will maintain mild and quiet weather 
through Tuesday. Low pressure will start to organize in the Central 
Plains tonight...and then slowly move toward northern Michigan through 
Thanksgiving day. This system will bring cooler and wetter weather 
by Wednesday and Thursday...though little in the way of snow is 
expected. 


Jz 


&& 


Short term.../issued at 429 am/...today 


Persistent for the past several nights...local observation showing areas of 
fog across much of northern Michigan...with visibilities ranging from 1 mile to 5 
miles. Do not expect widespread dense fog this morning...as some middle 
and upper level cloud cover spread into the region combined with southeast 
winds between 5 and 10 miles per hour. However will keep a mention of morning fog 
in most zones early this morning. 


Otherwise high pressure stretching from the North Atlantic into the 
eastern lakes...to remain a dominate feature through the afternoon. Dry air 
associated with this system will remain an influence over much of 
the state...as 850/500mb relative humidity lingers around 30 percent while surface dew points 
linger in the upper 30s and 850mb dew pt remain below 0c. Overall 
airmass and synoptic pattern over the northern lakes today...similar to 
Sunday...so will trend forecast today towards sundays outcome. Overall 
expect mostly sunny skies once again today with highs warming into 
the 50s. Winds turn more toward the southeast this afternoon...so will mention 
coolest temperatures over the eastern lakes with slightly warmer temperatures over the 
western lakes do to downsloping. 


Swr 


&& 


Long term.../issued at 429 am/...tonight and beyond 


High pressure and dry air over the eastern lakes to remain in control 
Monday night through Tuesday afternoon...while a Southern Plains storm 
system lifts into the Central Plains and an upper trough digs into 
the Central Plains. Model soundings and moisture forecasts show 850/500mb 
relative humidity lingering around 40 percent through 00z Wednesday. Will continue a dry forecast 
over the northern lakes Monday night and Tuesday. Low temperatures Tuesday in 
the middle 30s as airmass remains unchanged...afternoon temperatures in the 45 to 
50 degree range as some upper clouds increase over the state in 
advance of approaching surface and upper levels features. 


Tuesday night and Wednesday...Central Plains storm system lifts 
north into the upper Midwest Tuesday night before lifting north into 
The Straits and eastern Upper Michigan Wednesday. Model soundings and 
moisture forecasts showing moisture increase over the northern lakes through the period 
as the storm system lifts into northern Michigan. 850/500mb relative humidity will increase to 
around 80 percent while 850mb dew points increase from -8c Tuesday to 0c by 
12z Wednesday. Model soundings showing above freezing layer from the 
surface to around 4000 feet Tuesday night...extending to 5500 feet 
Wednesday. Therefore precipitation all in the form of rain through this 
period. Low temperatures in the 30s Tuesday night with highs in the middle 40s 
Wednesday. 


Wednesday night and Thursday...storm system over the northern lakes 
lingers but becomes stretched out across the state...as the low 
tries to lift north toward Hudson Bay. The digging 500mb trough drops 
south of the state and moves east over the Ohio Valley. Model 
soundings showing coldest 850mb air to linger west of the region and 
sweep south across the Ohio Valley. Over northern Michigan...850mb temperatures drop 
from around 0c/+1c Wednesday night to -3c Thursday. Model soundings 
showing above freezing layer extending from the surface through 4k feet 
Wednesday night dropping to around 2500 feet by 00z Friday. Will 
trend toward all rain event Wednesday night and much of Thursday 
afternoon. Will mention a mix rain/snow to all snow Thursday 
night...when vertical temperature profile on soundings show above freezing 
layer dropping under 1500 feet. Highs Thursday generally around 40 
most locations. 


Swr 


&& 


Marine.../issued at 429 am/ 


Winds and waves expected to remain below Small Craft Advisory criteria today 
through Tuesday...with winds primarily from the southeast. 
Strongest winds and highest waves today expected in The Straits 
and between the bridge and DeTour...however expected to remain below 
Small Craft Advisory. Fog this morning to diminish as surface high pressure and dry air 
linger across the eastern lakes. Clearing slowest over the eastern lakes 
once again today with overall southeast flow across the region and late 
Nov sun angle. Next chance of rain over the northern lakes nearshore 
waters...will be Tuesday night and Wednesday as a plains storm 
system lifts north into northern Michigan. 


Swr 


&& 


Aviation.../issued at 645 am/...valid for 12z tafs 


Current surface observation showing generally MVFR ceilings and visibilities over northern Michigan 
this morning...occasionally IFR visibilities at kapn. MVFR conds expected 
to improve to VFR around 14z/15z over kpln/ktvc as sun helps mix drier 
air to surface. Slower recovery at kapn as surface winds turn southeast with MVFR 
ceilings and visibility possible through much of the afternoon. Fog/stratus expected 
to redevelop again tonight...generally after 06z. 


Swr 


&& 


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


&& 


$$