Area Forecast Discussion
Issued by NWS Grand Rapids, MI

Home | Current Version | Previous Version | Text Only | Print | Product List | Glossary Off
Versions: 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50

000
FXUS63 KGRR 130831
AFDGRR

Area Forecast Discussion
National Weather Service Grand Rapids MI
330 AM EST Wed Nov 13 2019

LATEST UPDATE...
Synopsis/Discussion/Marine

.SYNOPSIS...
Issued at 330 AM EST Wed Nov 13 2019

- Another burst of snow late today through tonight for mainly
Central Lower

- Much quieter weather on the way later Thursday through the weekend

- Temperatures moderate a bit through next week

&&

.DISCUSSION...(Today through next Tuesday)
Issued at 330 AM EST Wed Nov 13 2019

Our main focus in the forecast will be on the system that will move
through the area later this afternoon into early Thursday, and bring
another burst of snow to the northern lakeshore and Central Lower.
We will be issuing a Winter Weather Advisory for the northern
lakeshore counties from Muskegon northward for 3 to 6 inches of new
snow.

There are two things going for this period of snow across the
northern sections of our area. The first one is a decent looking
short wave on water vapor coming through South Dakota this morning.
This will supply the large scale lift for the system. The other part
of this event is a bit of lake enhancement with a southerly flow.
H850 temps are still around -10C or colder, producing delta t`s
around the mid teens C.

We expect this event should not get out of hand due to the lake
effect, as forecast soundings indicate a fairly strong inversion
around 5-7k feet. This inversion will limit the amount of
instability from lake enhancement. The synoptic part of it across
Central Lower will be a 1-3, with the lake enhancement roughly
doubling that amount. Some consideration was given to Ottawa, and
Lake and Newaygo where 2-3 looks more widespread. Given the best
snows there will not be a big impact to the Wed evening commute, we
will hold them out for now and monitor the situation there.

Once the wave moves out early Thursday morning, it looks like we
will have a fairly quiet period of weather with moderating
temperatures. High pressure will slowly slide by, and the upper jet
will retreat back north into Canada.

We have a small shot of precipitation Sunday night into Monday
across the NW with a wave missing us to the NW.

&&

.AVIATION...(For the 06Z TAFS through 06Z Wednesday night)
Issued at 154 AM EST Wed Nov 13 2019

The lake effect cloud cover and snow showers are in the process of
dissipating/moving out as the flow becomes more southerly. This
should clear out the ceilings of 2500-3500 ft for a bit. We will
have ceilings of around 15k ft come in ahead of the next system. We
expect wind gusts of around 25 knots or so to develop by late
morning.

Lower clouds will arrive later this afternoon and this evening,
especially at the more northern sites. KMKG and KGRR could see
some light snow develop toward the end of the period. This could
bring MVFR conditions in with it.

&&

.MARINE...
Issued at 330 AM EST Wed Nov 13 2019

We will be leaving the marine headlines as they are with this
forecast package. The more solid gale winds will be north of
Muskegon, but it will be close enough elsewhere to leave the
headline in place. The lakeshore flood advisory also looks good. As
mentioned in previous discussions, the flow direction will limit the
lakeshore erosion a bit across the south being more parallel to the
shore vs. being onshore.

&&

.GRR WATCHES/WARNINGS/ADVISORIES...
MI...Winter Weather Advisory from 1 PM this afternoon to 10 AM EST
 Thursday for MIZ037-043-050.

Lakeshore Flood Advisory from 9 AM this morning to 4 PM EST this
     afternoon for MIZ037-043-050-056.

LM...Gale Warning from 9 AM this morning to 4 PM EST this afternoon
     for LMZ844>849.

&&

$$

SYNOPSIS...NJJ
DISCUSSION...NJJ
AVIATION...NJJ
MARINE...NJJ


USA.gov is the U.S. government's official web portal to all federal, state and local government web resources and services.