Area Forecast Discussion
Issued by NWS Grand Rapids, MI

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FXUS63 KGRR 040824
AFDGRR

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE GRAND RAPIDS MI
325 AM EST THU FEB 4 2016

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

.SYNOPSIS...
ISSUED AT 325 AM EST THU FEB 4 2016

TEMPERATURES WILL AVERAGE NEAR TO SLIGHTLY ABOVE NORMAL THROUGH
THE REST OF THE WEEK AND WEEKEND WITH A FEW LIGHT SNOW SHOWERS
AND FLURRIES. THERE IS POTENTIAL FOR A STRONGER CLIPPER SYSTEM TO
BRING MORE WIDESPREAD SNOW SUNDAY INTO MONDAY. MUCH COLDER WEATHER
IS ANTICIPATED FOR MOST OF NEXT WEEK.

&&

.SHORT TERM...(TODAY THROUGH SATURDAY)
ISSUED AT 325 AM EST THU FEB 4 2016

LIGHT SNOW SHOWERS AND FLURRIES WILL LINGER THIS MORNING AIDED BY
ANOTHER SHORTWAVE THAT WILL PUT MAINLY OUR FAR SOUTHERN FCST AREA
IN AN AREA OF STRONGER PVA THIS MORNING THAT WILL ENHANCE LIGHT
SNOW SHOWERS. THE PCPN WILL TAPER OFF THIS AFTERNOON IN SUBSIDENCE
UNDER THE HIGH PRESSURE RIDGE WHICH WILL BUILD IN.

DRY WX WILL CONTINUE THROUGH THE EVENING BEFORE A TROUGH OF LOW
PRESSURE BRINGS MORE LIGHT SNOW SHOWERS AND FLURRIES LATE TONIGHT
INTO EARLY FRIDAY. THE FLOW WILL BECOME ANTICYCLONIC AND RESULT IN
DRY WEATHER FOR FRIDAY AFTERNOON AND EVENING.

ANOTHER LOW PRESSURE SYSTEM TRACKING ACROSS THE NORTHERN GREAT
LAKES REGION WILL CAUSE LIGHT SNOW SHOWERS TO REDEVELOP MAINLY
OVER OUR FAR NW FCST AREA LATE FRIDAY NIGHT AND THEN ACROSS OUR
NORTHERN FCST AREA NORTH OF I-96 SATURDAY. ANY SNOW ACCUMULATIONS
THROUGH THE SHORT TERM FCST PERIOD WOULD BE VERY LIGHT AT
GENERALLY UNDER AN INCH.

.LONG TERM...(SATURDAY NIGHT THROUGH WEDNESDAY)
ISSUED AT 325 AM EST THU FEB 4 2016

OVERALL IT WOULD SEEM TO ME THE TREND OVERALL IS TOWARD COLDER
TEMPERATURE. THE COLDEST TEMPERATURES WILL BE THE MIDDLE OF NEXT
WEEK IN THE WEDNESDAY/THURSDAY TIME FRAME. TEMPERATURES SHOULD STAY
IN THE 20S IN THE AFTERNOON BY THEN. THE PATTERN FAVORS MOSTLY LAKE
ENHANCED SNOWFALL. IF YOU LIVE NEAR OR WEST OF US-131 PLAN ON SNOW
MOST OF THE TIME STARTING SUNDAY NIGHT. IF YOUR EAST OF THERE PLAN
ON PARTLY CLOUDY SKIES WITH FLURRIES FOR THE MOST PART.

THERE IS BETTER AGREEMENT BETWEEN THE GFS AND ECMWF FOR NEXT WEEK
BUT I STILL HAVE QUESTION ABOUT THIS. THE QUESTION IN MY MIND IS
DOES THE MJO WARM PHASE WIN THE DAY OR DOES THE STRATOSPHERE WARMING
EVENT TAKE THE DAY (WILL IT BE COLDER OR WARMER THAN NORMAL NEXT
WEEK)?

ON THE ONE HAND WE HAVE AN MJO IN PHASE 4...WARM FOR THE GREAT
LAKES...FAVORING RIDGING OVER THE EASTERN UNITED STATES. MEANWHILE
WE HAVE A VERY IMPRESSIVE STRATOSPHERIC WARMING EVENT OVER RUSSIAN
THAT MOVES INTO WESTERN NORTH AMERICA EARLY NEXT WEEK. THIS IS ONE
THE OF THE STRONGEST EVENTS I HAVE SEEN THIS YEAR. MAYBE STRONGER
THAN ANYTHING THAT HAPPENED LAST WINTER ACTUALLY. THESE EVENTS SPLIT
THE POLAR VORTEX INTO TWO PARTS AND THE MODELS ALL SHOW THIS
STARTING TO HAPPEN BY THE MIDDLE OF NEXT WEEK. CURRENTLY THE CENTER
OF THE POLAR VORTEX IS NORTH OF GREENLAND. BY THURSDAY WE SEE BOTH
THE ECMWF AND GFS AND THERE ENSEMBLES SHOWING IT MOVING SOUTHWEST TO
NORTHERN HUDSON BAY. WHILE THIS IS GOING ON THERE ARE TWO STRONG
EAST ASIAN JETS THAT HEAD ACROSS THE DATELINE. THE FIRST ONE IS
CURRENTLY NEAR THE DATELINE AND IT SEEMS TO HELP STRENGTHEN A STORM
IN THE GULF OF ALASKA AND DOES NOT DO WHAT WOULD BE TYPICAL...HEAD
EAST TO THE WEST COAST OF THE UNITED STATES. THAT IN TURN HELPS
BUILD THE WESTERN RIDGE WHICH HELPS SEND NORTHERN STREAM WAVES
FARTHER SOUTH INTO THE NORTHERN UNITED STATES. THIS IS WHAT BRINGS
THAT SYSTEM INTO OUR AREA ON MONDAY. THEN THROUGH THERE IS A SECOND
180 TO 200 KNOT EAST ASIAN JET THAT HEADS INTO THE BACK SIDE OF THAT
GULF OF ALASKA SYSTEM. THAT HELPS DEEPEN THE TROUGH EVEN FARTHER AND
BUILDS THE WESTERN RIDGE EVEN MORE.  SO BY THE MIDDLE OF NEXT WEEK
WE HAVE A RATHER DEEP EASTERN TROUGH. THE ECWMF SHOWS THE AO GOING
SIGNIFICANTLY NEGATIVE BY THE MIDDLE OF NEXT WEEK (FROM THE 03/12Z
RUN).  THE GFS HAS IT GETTING AS NEGATIVE AS IT DID DURING THE
COLDEST WEATHER WE HAD LAST MONTH. ALL OF THIS SEEMS TO SUGGEST
COLDER WEATHER WILL PREVAIL. ALSO IT WOULD KEEP ANY SOUTHERN STREAM
SYSTEMS FROM IMPACTING OUR WEATHER. ANY PRECIPITATION WOULD BE FROM
CLIPPER SYSTEMS AND OR LAKE EFFECT SNOW.

WE HAVE ONE CLIPPER SYSTEM THAT PASSES NORTH OF LAKE SUPERIOR FRIDAY
NIGHT. BEHIND THAT IS THE NEXT CLIPPER SYSTEM. THAT ONE IS THE ONE
THAT DIVES MUCH FARTHER SOUTH... TO WESTERN LAKE SUPERIOR BY SUNDAY
EVENING. ALL OF THE MODELS SHOW THIS SYSTEM CONTINUING TO DIG
SOUTHEAST BEING OVER LAKE ERIE BY TUESDAY. THIS IS ALL RELATED TO
THAT BUILDING WESTERN RIDGE.  ALL MODELS CLOSE OFF A 500 MB LOW OVER
OVER CENTRAL LAKE MICHIGAN BY MONDAY AFTERNOON. THAT SYSTEM IS OVER
CENTRAL OHIO BY TUESDAY. CLEARLY THIS WOULD BRING LAKE ENHANCED SNOW
TO THE AREA MONDAY INTO TUESDAY. BEYOND THAT THE TRULY ARCTIC AIR
COMES IN AND THAT WOULD RESULT IN C0NTINUED LAKE EFFECT INTO AT
LEAST THURSDAY.

SO...IF THE MJO WERE TO PREVAIL... THAT MONDAY SYSTEM WOULD STAY
FARTHER NORTH AND WE WOULD NOT GET INTO THE COLD AIR DURING THE
MIDDLE OF NEXT WEEK. GIVEN HOW THE MODELS KEEP TRENDING TOWARD
COLDER I WILL LEAN THAT WAY FOR NOW AND CALL IT GOOD.


&&

.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z THURSDAY NIGHT)
ISSUED AT 1201 AM EST THU FEB 4 2016

EXPECTATION IS THAT MVFR CEILINGS WILL PERSIST THE REMAINDER OF
THE NIGHT AND INTO THE MIDDAY HOURS OF THURSDAY. SNOW SHOWERS WILL
BE MOST PREVALENT THE NEXT FEW HOURS...AND SLOWLY DIMINISH EVEN
FURTHER TO FLURRIES AS WE HEAD PAST 12Z. SO...A FEW LOCATIONS MAY
BE IMPACTED BY 3-5SM VISIBILITIES DUE TO SNOW SHOWERS THROUGH
12Z...BUT WE SHOULD BE TRENDING MORE AND MORE TOWARDS 6SM -SN.
KJXN MAY SEE SOME IFR CONDITIONS THROUGH 09Z AS WELL...AS A
SURFACE TROUGH MOVES EAST THROUGH THE AREA.

WE SHOULD SEE CONDITIONS TREND TO VFR IN ALL AREAS THURSDAY
AFTERNOON...BUT MVFR CEILINGS MAY MAKE A REAPPEARANCE THURSDAY
EVENING TOWARDS KMKG AFTER 00Z.


&&

.MARINE...
ISSUED AT 325 AM EST THU FEB 4 2016

NW WINDS OF AROUND 10 TO 15 KTS WILL BACK TO THE WEST THEN SW
TODAY AND CONTINUE TO GRADUALLY DIMINISH. WAVE HEIGHTS WILL
GRADUALLY SUBSIDE THROUGH THE DAY AS WELL.

&&

.HYDROLOGY...
ISSUED AT 258 PM EST WED FEB 3 2016

MINOR FLOODING IS POSSIBLE THIS WEEK... ESPECIALLY IN LOWLAND AREAS
NEAR RIVERS. SOME RIVERS MAY EXCEED BANKFULL DUE TO SNOW MELT AND
PRECIPITATION FROM THE LAST STORM. TOTAL PRECIPITATION OF ONE TO
AROUND ONE AND A HALF INCHES FELL. RIVER FLOOD ADVISORIES HAVE BEEN
ISSUED FOR SYCAMORE CREEK AT HOLT... FLAT RIVER AT SMYRNA... ROGUE
RIVER AT ROCKFORD... MAPLE RIVER AT MAPLE RAPIDS AND GRAND RIVER AT
IONIA.

&&

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

&&

$$

SYNOPSIS...LAURENS
SHORT TERM...LAURENS
LONG TERM...WDM
AVIATION...DUKE
HYDROLOGY...63
MARINE...LAURENS


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