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 250829
AFDGRR

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE GRAND RAPIDS MI
330 AM EST WED FEB 25 2015

LATEST UPDATE...
SYNOPSIS/SHORT TERM/LONG TERM

.SYNOPSIS...
ISSUED AT 330 AM EST WED FEB 25 2015

AN ARCTIC AIRMASS WILL REMAIN FIRMLY ENTRENCHED IN THE GREAT LAKES
REGION THROUGH FRIDAY. A WEAK SYSTEM WILL BRING A FEW LIGHT SNOW
SHOWERS TO FAR SOUTHERN LOWER MICHIGAN TONIGHT INTO THURSDAY
MORNING. HIGH PRESSURE WILL BUILD IN TO PRODUCE FAIR BUT COLD
WEATHER THURSDAY THROUGH SATURDAY. TEMPERATURES WILL FINALLY
UNDERGO A GRADUAL MODERATING TREND LATE THIS WEEKEND INTO EARLY
NEXT WEEK.

&&

.SHORT TERM...(TODAY THROUGH FRIDAY)
ISSUED AT 330 AM EST WED FEB 25 2015

FAIRLY TRANQUIL AND COLD WEATHER IS ANTICIPATED THROUGH THE SHORT
TERM FCST PERIOD. A FEW LIGHT SNOW SHOWERS AND FLURRIES WILL
LINGER INTO THIS MORNING BUT WITH VERY LITTLE TO NO ADDITIONAL
SNOW ACCUMULATION. MOST OF THE DAY WILL BE DRY BUT COLD WITH A MIX
OF SUN AND CLOUDS. MAX TEMPS WILL ONLY REACH 10 TO 15 DEGREES.

A WEAK SYSTEM MOVING ESE FROM THE NORTHERN PLAINS STATES EARLY
THIS MORNING WILL BRING A FEW LIGHT SNOW SHOWERS AND FLURRIES TO
OUR SOUTHERN FCST AREA NEAR TO MAINLY SOUTH OF I-96 TONIGHT INTO
THURSDAY MORNING... WITH VERY LIGHT SNOW ACCUMULATIONS OF UNDER AN
INCH.

BEYOND THAT HIGH PRESSURE WILL BUILD IN TO PRODUCE FAIR BUT COLD
WX THURSDAY AFTERNOON THROUGH FRIDAY. MAX TEMPS THURSDAY WILL
STRUGGLE TO REACH THE UPPER SINGLE DIGITS TO LOWER TEENS AND MINS
THURSDAY NIGHT WILL FALL TO BELOW ZERO ACROSS OUR AREA AS SKIES
CLEAR AND WITH LIGHT WINDS AND EXPANSIVE SNOW COVER IN PLACE. MAX
TEMPS FRIDAY WILL STRUGGLE TO REACH THE LOWER TO MIDDLE TEENS IN
SPITE OF LOTS OF SUN AFTER A VERY COLD START TO THE DAY.

.LONG TERM...(FRIDAY NIGHT THROUGH TUESDAY)
ISSUED AT 330 AM EST WED FEB 25 2015

UPPER AIR PATTERN SHIFT IS STILL FORECAST TO OCCUR BY THE 00Z MODEL
RUNS DURING THE LONG TERM. THE PERSISTENT UPPER TROUGH IS IN THE
PROCESS OF LIFTING OUT FRIDAY NIGHT. BY EARLY NEXT WEEK A SOUTHWEST
FLOW DEVELOPS ACROSS THE LOWER 48...FROM THE SOUTHWEST U.S. TO THE
GREAT LAKES.

THERE ARE TWO MAIN ITEMS TO KEEP AN EYE ON THROUGH THE PERIOD. THE
FIRST IS THE SNOW EVENT FOR SUNDAY AND SUNDAY NIGHT. IT REMAINS AN
EVENT WITH NO SURFACE LOW TO KEY ON. SNOW IS PRODUCED VIA A WEAK
FRONTAL BOUNDARY SLIPPING THROUGH THE AREA COUPLED WITH AN UPPER
LEVEL SHORT WAVE AND ISENTROPIC LIFT. IT APPEARS TO BE A 2-5 INCH
SNOW POTENTIALLY FOR THE SOUTHERN HALF OF THE FORECAST AREA. WE
STILL HAVE PLENTY OF TIME TO NAIL DOWN THE DETAILS WITH THIS SYSTEM.

THE SECOND SIGNIFICANT FEATURE TO KEEP AN EYE ON IS A SYSTEM NEXT
WEEK IN THE TUESDAY OR WEDNESDAY TIME FRAME. LOW CONFIDENCE IN THIS
TIME FRAME AS THE GFS IS QUICKER...BRINGING A DEEP LOW THROUGH THE
AREA ON TUESDAY. THE ECMWF AND CANADIAN ARE SLOWER AND BRING THE
SYSTEM THROUGH ON WEDNESDAY. AT THIS POINT...SIDING WITH THE ECWMF
AND CANADIAN AND THE SLOWER SYSTEM. THE SYSTEM TAPS GULF MOISTURE IN
DEEP SOUTHERLY FLOW. PRECIPITATION TYPE ISSUES COME INTO PLAY
TUESDAY NIGHT IN THE ECMWF/CANADIAN SOLUTIONS WITH +4 TO +6 850MB
AIR SURGING IN FROM THE SOUTH. THESE VALUES WOULD YIELD RAIN AS THE
PRECIP TYPE ALONG I94. MODELS ARE HAVING ISSUES WITH THIS SYSTEM AS
ITS DRIVEN BY A WAVE EJECTING OUT OF THE SOUTHWEST U.S. TROUGH. WE
WILL BE MONITORING TRENDS WITH THIS SYSTEM IN THE COMING DAYS.

&&

.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z WEDNESDAY NIGHT)
ISSUED AT 1159 PM EST TUE FEB 24 2015

PREDOMINATELY VFR WEATHER IS EXPECTED TONIGHT AND WEDNESDAY BEHIND
THE ARCTIC FRONT WHICH IS CURRENTLY PASSING THROUGH. THERE MAY
STILL BE SOME BRIEF VSBYS OF 2-4 MILES THROUGH 08Z IN SOME OF THE
SCATTERED SNOW SHOWERS BEFORE THE FRONT IS COMPLETELY THROUGH.
ALSO SOME MVFR CIGS/VSBYS AND LIGHT SNOW SHOWERS MAY PERSIST ALONG
THE LAKESHORE AT MKG OVERNIGHT INTO EARLY WEDNESDAY. SFC WINDS
WILL DIMINISH OVERNIGHT TO LESS THAN 10 KNOTS AND REMAIN LIGHT ON
WEDNESDAY.

&&

.HYDROLOGY...
ISSUED AT 224 PM EST TUE FEB 24 2015

CURRENTLY NO SUSPECTED ICE JAMS AND RIVER LEVELS ARE HOLDING RATHER
STEADY. FORECAST CALLS FOR BELOW FREEZING TEMPERATURES INTO NEXT
WEEK WITH OCCASIONAL SNOW OPPORTUNITIES. THE RISK OF FLOODING IS
FAIRLY LIMITED UNTIL A NOTABLE WARM-UP OR RAIN EVENT.

&&

.GRR WATCHES/WARNINGS/ADVISORIES...
MI...NONE.
LM...NONE.
&&

$$

SYNOPSIS...LAURENS
SHORT TERM...LAURENS
LONG TERM...DUKE
AVIATION...MEADE
HYDROLOGY...CAS






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