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000 
FXUS63 KAPX 261743
AFDAPX

Area Forecast Discussion
National Weather Service Gaylord MI
143 PM EDT Sun Mar 26 2017

.UPDATE...
Issued at 142 PM EDT Sun Mar 26 2017

Some thunder was added to areas near Saginaw Bay this afternoon,
as lightning strikes have been noted as close as just off the tip
of the thumb.

UPDATE Issued at 1043 AM EDT Sun Mar 26 2017

Chilly rains continue in much of northern MI. Initial batch
has lifted out of eastern upper MI, with another lifting across w
central lower. A tendency for lighter showers to fill in between 
these larger areas has also been seen this morning. 12Z APX 
observed sounding illustrates the potent warm nose just off the 
surface, with 10C air 1500ft agl. We'd only need a very tall 
building to experience 50f wx this morning!

The main issue is of course where temps remain at, or just below
freezing. This is the case in the Straits area and points north.
Temps are slowly, very slowly, drifting higher. Diurnal heating
(even thru the cloud cover) will help that along. But HRRR and RAP
progs are very reluctant to warm temps much, especially in
central/northern Chip Co. The HRRR in particular wants to keep a
lot of the county right at 32f essentially all day. That looks a
smidge pessimistic to me. But, with Kinross and even Drummond Isl
still only at 31f, and with patchy light precip expected to
continue, will need a freezing precip mention deeper into the day.

Will thus extend the advisory for Chip until 4 pm. Think Mack,
with more of a marine influence, will be able to drop off at noon
as originally planned.

&&

.NEAR TERM...(Today through Tonight)
Issued at 336 AM EDT Sun Mar 26 2017

...Unsettled weather continues...

High Impact Weather Potential...icing potential through this
morning.

Pattern Synopsis/Forecast...Stacked/occluded low pressure system
is over western Illinois early this morning lifting northeastward...
associated warm front draped eastward through northern Ohio. 
Surface high pressure is pivoting through the northern lakes
region with the high center over Quebec. Push of warmer air and
feed of Gulf moisture into northern Michigan is underway bringing
a fairly widespread batch of precipitation into our area. Strong 
low to mid level warming underway (H8 temp was already +5C on our 
00Z sounding) thus precipitation is mostly liquid at this
juncture. Temps are hovering freezing in many areas, but with
lower dewpoints and room for evap cooling...particularly in
eastern upper Michigan.

Primary Forecast Concerns...ice accumulations this morning.

Today: Stacked low pressure system will continue to fill and rotate
up into lower Michigan through the course of the day. Per regional
radar plots, several waves of rainfall will be sliding up through
the region through the day and I have attempted to add some 
timing detail to PoPs based on trends and hi-res guidance QPF. Of
course the bigger issue is freezing rain early on. As mentioned,
temperatures are around the freezing mark for a chunk of northern
lower Michigan and below freezing in eastern upper Michigan where
lower dewpoints and evap cooling have lower temps in the last few
hours. Surface temps will rise to well above freezing today but it
will take several more hours to do so, especially in eastern
upper where around two tenths of an inch of ice accumulation
remains a good bet through this morning. 

Ongoing advisories still look fine. Northern lower Michigan
advisory drops at 8 am while eastern upper goes until noon. And
based on projected hourly temperature forecasts, that seems good
for now. Northern lower MI advisory might have to be extended an
hour or two, but will see how that goes.

Tonight: Final big surge of moisture/precip swings up through the
region this evening before main moisture feed/warm conveyor feed
gets pinched off and shunted eastward. Rainfall coverage/amounts 
will diminish thereafter although linger as light rain or drizzle
and some fog through the overnight hours...as trailing deformation
axis slides up through northern Michigan. But temperatures will 
remain well above freezing...thus no concerns for freezing precip 
tonight. 

&&

.SHORT TERM...(Monday through Tuesday)
Issued at 336 AM EDT Sun Mar 26 2017

...Rather uneventful period of weather...

High Impact Weather Potential: Nothing significant.
  
Pattern Synopsis/Forecast: Split flow dominated NOAM mid and upper 
level flow pattern set to continue for the foreseeable future, with 
the Arctic jet well removed to the north, leaving much of the 
northern Conus under the influence of a much milder Pacific 
originated flow regime. This will allow temperature to reach or 
exceed end of March long term normals for much of this upcoming work 
week. Pattern also looks to dry out a bit, with current rain 
producing system slowly exiting stage right Monday, allowing 
southern extent of high pressure to build overhead Monday night 
through at least mid-week.

Primary forecast concerns: Lingering light rain concerns to start 
the work week. Temperature and cloud trends thereafter.

Details: Plenty of low clouds, along with some drizzle and patches 
of light showers expected to linger into at least Monday morning as 
weakening mid level wave and its attendant surface reflection pass 
through the region (really just remnants of the current system 
responsible for periods of rain and freezing rain the last few 
days). Surface temperatures by then look to be safely above 
freezing, so not looking at any freezing rain concerns. System drags 
a weak cold front through our area as it passes, with some hints 
that a weak area of low pressure will develop along it Monday night 
as a secondary mid level wave approaches. Not strong support for 
this solution, but should it occur we could be looking at some more 
light showers across at least southern areas through Monday night.

Southern extent of elongated Canadian high pressure makes a more 
aggressive push into the northern Lakes Tuesday and Tuesday night. 
Dry northerly flow looks to really do a number on lingering low 
clouds, with skies clearing from north to south Tuesday. This sets 
the stage for a clear and seasonably chilly Tuesday night.

.LONG TERM...(Wednesday through Saturday) 
Issued at 336 AM EDT Sun Mar 26 2017

...Threat for more rain returns by the end of the week...

After a dry mid-week period, active southern stream looks to 
potentially send another fairly moisture rich system in our 
direction in the Thursday night through Saturday time frame. Still 
plenty of uncertainty on this idea, with at least some hints 
southern system may remain detached from more progressive flow and 
largely pass by to our south. Overall guidance blends definitely 
support at least some rain potential, and this will remain the way 
this forecast will be trended until a more stable solution is 
realized. Thermal profiles support another rain event should this 
system occur, although suppose a light wintry mix is possible 
Thursday night with intial surge of evaporational cooling. Shouldn't 
be a big deal with both duration and amounts of any wintry 
weather remaining limited.

&&

.AVIATION...(For the 18Z TAFS through 18Z Monday afternoon)
Issued at 142 PM EDT Sun Mar 26 2017

Mainly IFR.

Low pressure in nw IL continues to slowly approach, and will cross
lower MI tonight. This system will be weakening with time, but
abundant moisture is already in place. Showers and IFR cigs are
common, and for a period tonight expect fog to become prevalent
(as winds diminish). The system will move off to our east Monday,
with some gradual improvement (especially in vsbys), though more
rapid improvement will wait until after 18z Monday.

Easterly breezes will go light/variable this evening, with a
light nw breeze Monday morning.

&&

.MARINE...
Issued at 336 AM EDT Sun Mar 26 2017

Gusty easterly winds will lead to small craft advisory conditions
on parts of the Great Lakes today. Winds diminish heading into
tonight and remain on the lighter side through Monday.


&&

.APX WATCHES/WARNINGS/ADVISORIES...
MI...WINTER WEATHER ADVISORY until 4 PM EDT this afternoon for MIZ008.
LH...SMALL CRAFT ADVISORY until 7 PM EDT this evening for LHZ345>348.
LM...NONE.
LS...SMALL CRAFT ADVISORY until 2 PM EDT this afternoon for LSZ321-
     322.
&&

$$

UPDATE...JZ
NEAR TERM...TBA

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