Area Forecast Discussion
Issued by NWS Grand Rapids, MI

Home | Current Version | Previous Version | Graphics & Text | Print | Product List | Glossary On
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
438
FXUS63 KGRR 231745
AFDGRR

Area Forecast Discussion
National Weather Service Grand Rapids MI
145 PM EDT Wed Aug 23 2017

LATEST UPDATE...
Aviation

.SYNOPSIS...
Issued at 325 AM EDT Wed Aug 23 2017

High pressure from Canada will bring dry weather with low humidity
and relatively cool temperatures this week. The fair weather with
cooler than normal temperatures will continue into early next
week.

&&

.SHORT TERM...(Today through Friday)
Issued at 325 AM EDT Wed Aug 23 2017

No significant weather expected in the near term as dry northwest
flow is in place and sfc ridge is building in. The only potential
wrinkle is for some isolated afternoon showers that could result
from lake enhancement today and as a result of a digging shortwave
trough on Thursday. In both cases, soundings only show shallow
moisture which will limit chances enough to leave precip out of
the forecast for now.

Trough axis moves east by Friday with zonal flow and heights
rising a bit. Temperatures should moderate slightly but still
running a bit below the seasonal norms of near 80 maxes and
mins near 60.

.LONG TERM...(Friday night through Tuesday)
Issued at 325 AM EDT Wed Aug 23 2017

More likely than not, the long term period will be dry. Canadian
high pressure will control our weather from Friday night through
Sunday night. Very comfortable conditions are expected. Temperatures
Friday night will be mostly in the 40s and then slowly rise to the
50s for the rest of the period. Highs in the mid 70s are expected
through the period.

Very small chances for showers will enter the picture Monday into
Tuesday. Both the ecmwf and gfs show a short wave rotating through
the upper trough during this time. Moisture will be limited,
however, and widespread rain probably isn`t going to occur.

Although the medium range models are not in good agreement, the
remnants of the tropical system probably won`t affect us. Cold
fronts moving through the Great Lakes will tend to push any system
moving north from the Gulf eastward toward the Mid Atlantic.

&&

.AVIATION...(For the 18Z TAFS through 18Z Thursday afternoon)
Issued at 146 PM EDT Wed Aug 23 2017

No IFR conditions expected through the period. Scattered clouds
just under 3000 ft AGL may briefly spread into broken ceilings,
particularly at the KAZO, KBTL and KGRR terminals. Certainty and
possible durations for any ceilings are both very limited and
therefore not mentioned in TAFs. Cloud layers will climb above
3000 feet by around 20Z and dissipate around 00Z with diminishing
sunlight.

&&

.MARINE...
Issued at 325 AM EDT Wed Aug 23 2017

Winds and waves will be decreasing today and the Small Craft
Advisory should be able to be cancelled late this afternoon. There
is a very low chance of a shower and perhaps a waterspout on
Thursday, but chances are low enough to leave out of the forecast
for now.

&&

.HYDROLOGY...
Issued at 1213 PM EDT Wed Aug 23 2017

Area rivers are around normal levels for the time of the year and
well below bankfull. The rivers have already recovered from the
recent rainfall. No significant precipitation is expected through
the weekend, so no river issues are expected.

&&

.GRR WATCHES/WARNINGS/ADVISORIES...
MI...Beach Hazards Statement until 11 PM EDT this evening for MIZ064-
     071.

     Beach Hazards Statement until 6 PM EDT this evening for MIZ037-
     043-050-056.

LM...Small Craft Advisory until 6 PM EDT this evening for LMZ846>849.

     Small Craft Advisory until 11 PM EDT this evening for LMZ844-845.

&&

$$

SYNOPSIS...Ostuno
SHORT TERM...Ostuno
LONG TERM...04
AVIATION...TJT
HYDROLOGY...63
MARINE...Ostuno



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