Area Forecast Discussion
Issued by NWS Grand Rapids, MI

Home | Current Version | Previous Version | Graphics & Text | 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

FXUS63 KGRR 132341

Area Forecast Discussion
National Weather Service Grand Rapids MI
741 PM EDT Tue Mar 13 2018


Issued at 330 PM EDT Tue Mar 13 2018

Lake effect snow showers will linger into this evening before
tapering off overnight. A ridge of high pressure will build in and
bring fair weather mid to late week and into the weekend.
Temperatures will average fairly close to normal through the rest
of the week and weekend.


.SHORT TERM...(This evening through Thursday night)
Issued at 330 PM EDT Tue Mar 13 2018

North northwest flow light lake effect snow showers will continue
late this afternoon and evening with h8 temps of -11 to -14 C
yielding delta t/s in the upper teens to lower 20s. Any additional
snow accumulations through this evening will be very light at
under an inch. The light snow showers will taper off overnight as
h8 temps moderate a bit toward daybreak and a mid level ridge
begins to build in from the northwest.

Fair weather will return Wednesday as ridging takes hold of the wx
pattern. A cold front will come through dry across the vast
majority of our fcst area Wednesday evening. However a few
flurries or very light snow showers may clip our far northern fcst
area from early Thursday morning through Thursday afternoon. High
temperatures Thursday will only reach the upper 20`s to middle
30`s with brisk northwest winds.

.LONG TERM...(Friday through Tuesday)
Issued at 330 PM EDT Tue Mar 13 2018

The long term looks to be mainly dry with temperatures that will be
up and down, which is not atypical for this time of year. We start
out the long term Friday on the cold side of normal warm up a bit
into the weekend and then cool off once again early next week. No
major warm up and no major storms are forecast to affect our area.

Dry weather is anticipated from Friday through Monday as a high
pressure ridge at the surface remains situated across the area. A
surface low will traverse the Ohio Valley on Saturday keeping its
precipitation south of the state. A cold front will then move
through the area on Sunday but given the lack of moisture associated
with it we expecting it to come through dry. Aloft through the
Friday through Monday period the Great Lakes will be situated in a
confluent flow regime. The confluent flow aloft and dry air in place
in the 1000-700mb layer leads to a high confidence of a dry forecast
during this time frame.

The next weather maker potentially for our area will come Monday
Night into Tuesday. The Canadian, ECMWF and GFS all eject an upper
low out of the western U.S. trough and swing it southwest of us
through Missouri into the Ohio Valley. Southwest Michigan will be on
the northern periphery of this system. The Canadian is the only
model of the three mentioned above to bring precipitation into
Southern Lower Michigan. Given confidence is low in precipitation
making it this far north only have a 20-30 pct chance of rain/snow
showers in the forecast.


.AVIATION...(For the 00Z TAFS through 00Z Wednesday evening)
Issued at 741 PM EDT Tue Mar 13 2018

Mainly VFR weather is expected next 24 hours as scattered snow
showers diminish tonight. Expect a SCT-BKN stratocumulus cloud
deck tonight with bases generally between 3000 and 5000 ft, then
some clouds around 10,000 ft arriving on Wednesday. North sfc
winds diminishing to around 10 kts this evening, becoming west-
southwest on Wednesday.


Issued at 330 PM EDT Tue Mar 13 2018

Water levels in most of the rivers across West Michigan will
continue to fall through the end of the week, with only the Portage
River near Vicksburg remaining above flood stage. Showers through
Wednesday morning will have no immediate impact on water levels, as
precipitation remains snow. A fairly dry weather pattern will then
develop Wednesday afternoon and last through early next week. Runoff
from snow melt could cause some minor rises in smaller streams by
the weekend, but renewed flooding is not expected.




SHORT TERM...Laurens
HYDROLOGY...Laurens is the U.S. government's official web portal to all federal, state and local government web resources and services.