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 231801
AFDGRR

Area Forecast Discussion
National Weather Service Grand Rapids MI
201 PM EDT Thu Mar 23 2017

LATEST UPDATE...
Aviation/Hydro

.SYNOPSIS...
Issued at 328 AM EDT Thu Mar 23 2017

High pressure will provide one more day of fair weather then rain
will move in tonight as the high moves east and low pressure
slowly moves towards Lower Michigan. The rain will persist
through the weekend.

&&

.SHORT TERM...(Today through Saturday)
Issued at 328 AM EDT Thu Mar 23 2017

Forecast issues include timing of precip this evening and p type
across the northeast interior. Dry wedge persists into this
evening as warm advection begins, so the POPS for this evening
were lowered. Expect scattered showers to arrive by 03Z as warm
advection increases with a few elevated thunderstorms possible as
lapse rates steepen. Left thunder out of the forecast for now but
isolated thunder may need to be added between 03z and 08Z.

Given the low dew points this evening, kept mention of freezing
rain across the NE zones where temps are most likely to wet bulb
down below freezing at the outset of the precip. Dew points come
up quickly in strong southerly flow, so do not expect any
persistent FZRA or impacts to travel.

The front is across the northern tier during much of Friday with
potential for strong north-south temperature gradient especially
if southern zones are able to clear out during the afternoon.
Front sags south on Saturday with more clouds and higher chances
for rain and cooler temperatures.

.LONG TERM...(Saturday night through Wednesday)
Issued at 328 AM EDT Thu Mar 23 2017

A showery and unsettled weather pattern will continue Sunday into
early next week. A low pressure system will continue to move slowly
northeast across the lower Great Lakes region Saturday night through
Sunday and bring occasional rain showers. High temperatures Sunday
should reach into the 50`s in spite of extensive cloud cover and
showers.

The wx pattern will remain unsettled as another low pressure system
over the Arklatex region on Monday moves northeast and brings our
area more showers Monday night into early Tuesday.

Fair weather should finally return Tuesday night through Wednesday
as northerly winds behind that system advect a cooler and drier
airmass in and a sfc high pressure ridge builds in from the
northwest.

&&

.AVIATION...(For the 18Z TAFS through 18Z Friday afternoon)
Issued at 146 PM EDT Thu Mar 23 2017

With the low levels remaining dry for most of the period...VFR
weather will prevail. A band of instability pivots northeastward
through the TAF sites this evening. This is associated with the
convection down in IA. Thus I added a risk for thunderstorms in
the TAF forecasts for a few hours.

The front associated with the convection stalls out just north of
the TAF sites. As a result the northern TAF sites could see a risk
for showers even into tomorrow. Further south...we will need to
monitor the gusty wind potential for Friday as a low level jet
will be in place.

&&

.MARINE...
Issued at 328 AM EDT Thu Mar 23 2017

Have issued a SCA for today north of Whitehall where waves will be
3 to 5 feet.


&&

.HYDROLOGY...
Issued at 146 PM EDT Thu Mar 23 2017

An active weather pattern starting Thursday night and lasting
through at least early next week will provide multiple episodes of
at light rain, and occasional periods of heavier rain. Thursday
night through Sunday, rainfall totals between 0.75 and 1.5 inches
will likely fall over the area, with the higher-end amounts favored
in Muskegon river basin. River levels will likely rise as a result.
Some rivers may eventually climb back to bankfull next week.

&&

.GRR WATCHES/WARNINGS/ADVISORIES...
MI...None.
LM...Small Craft Advisory until 8 PM EDT this evening for LMZ848-849.

&&

$$

SYNOPSIS...Ostuno
SHORT TERM...Ostuno
LONG TERM...Laurens
AVIATION...MJS
HYDROLOGY...CAS
MARINE...Ostuno



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