FXUS63 KMQT 090615 AAC
AFDMQT
AREA FORECAST DISCUSSION...UPDATED
NATIONAL WEATHER SERVICE MARQUETTE MI
115 AM EST WED DEC 9 2009
UPDATED FOR 06Z AVIATION DISCUSSION
.UPDATE... ISSUED AT 1105 PM EST
INHERITED FCST WAS IN GREAT SHAPE AND ONLY MINOR CHANGES WERE MADE
AS STORM IS CURRENTLY EVOLVING AS EXPECTED. WATER VAPOR IMAGERY AND
RUC ANALYSIS SHOW AN INCREASINGLY DYNAMIC SYSTEM HEADING ACROSS THE
CNTRL PLAINS. SFC LOW PRES OVER NCNTRL MO IS JUST BEGINNING TO HEAD
INTO A RAPID DEEPENING PHASE. IMPRESSIVE 3HR PRES FALLS OF 6-9MB ARE
NOTED IN WIDE SWATH FROM ERN IA/SRN WI INTO IN. PCPN SHIELD HAS BEEN
FILLING IN AND INTENSIFYING FROM IA INTO WI IN THE LAST FEW HRS
UNDERNEATH STRONGLY DIFFLUENT FLOW COUPLED UPPER JET STRUCTURE. VAD
WIND PROFILE FROM KMQT RADAR SHOWED LOW-LEVEL WINDS VEERING A LITTLE
S OF DUE E EARLIER IN THE EVENING WHICH RESULTED IN LAKE ENHANCED
SNOW DIMINISHING FOR A TIME IN MARQUETTE COUNTY. RECENTLY...WINDS
ARE BACKING A LITTLE N OF E...AND REFLECTIVITIES ARE BEGINNING TO
SHOWN AN UPTICK.
EXPECT BULK OF HEAVIEST SYNOPTIC SNOW TO FALL THRU THE MORNING HRS
WITH DIMINISHING TREND FROM SW TO NE DURING THE AFTN. LAKE
ENHANCEMENT WILL KEEP HVY SNOW GOING NEAR LAKE SUPERIOR INTO THE
EVENING HRS WED. THIS SHOULD END UP BEING A VERY IMPRESSIVE LAKE
ENHANCED SNOW EVENT FOR NCNTRL UPPER MI. TRAVEL WILL BE DANGEROUS
ACROSS ALL OF THE FCST AREA WED...BUT CONDITIONS WILL BE ESPECIALLY
DANGEROUS IN NCNTRL UPPER MI GIVEN PERSISTENT HVY SNOW/STRONG
WINDS/SIGNIFICANT BLSN.
&&
.SYNOPSIS... ISSUED AT 436 PM EST
12Z RAOBS/LATEST WV IMAGERY AND RUC ANALYSIS SHOW DEEPENING TROF
OVER THE W WITH RDGING EXTENDING FM THE SE INTO THE GRT LKS. WEAK
RDG AXIS DOMINATES THE UPR GRT LKS THIS MRNG...BUT AIRMASS IS
SUFFICIENTLY COLD/MOIST FOR SOME LES WITH H85 TEMPS ARND -15C. 12Z
APX RAOB SHOWS A RELATIVELY MOIST SFC-H8 LYR BLO SUBSIDENCE INVRN
ASSOCIATED WITH THE RDG. HOWEVER... WINDS ARE RELATIVELY LGT...SO
LES MORPHOLOGY IS RATHER CLUMPY VS WELL DEFINED BANDS. BUT BULK OF
SHSN VSBL ON THE MQT RADAR HAVE SHIFTED OFFSHORE AS NLY WIND
COMPONENT HAS DIMINISHED. TURNING TO THE SW...A POTENT SHRTWV IS
POISED TO LIFT NE OUT OF THE DESERT SW. H3/H5/H7 WINDS OF 140KT/
100KT/70KT WITHIN JET MAX ROUNDING THE BASE OF THE TROF SPEAK TO THE
INTENSITY OF THIS SHRTWV. THE GLFMEX HAS OPENED UP AHEAD OF THIS
SHRTWV WITH H85 DWPTS AOA 10C MOVING TOWARD THE CENTRAL MS VALLEY IN
THE SLY FLOW E OF SFC/H85 LO IN SE COLORADO. THICKER MID/HI CLD WELL
IN ADVANCE OF THIS SHRTWV/LO ARE MOVING INTO UPR MI OVER THE WEAK
RDG IN PLACE. THE LEADING EDGE OF THE SN HAS REACHED NCNTRL WI TO
NEAR MNM AS OF NOON.
&&
.SHORT TERM /TNGT AND WED/... ISSUED AT 436 PM EST
FCST CONCERNS THIS PD ARE OBVIOUS AND CONCERN IMPACT OF DEEP LO PRES
FCST TO LIFT NE FM THE PLAINS TO NE LWR MI/NRN LK HURON BY 00Z THU.
CONSIDERATION OF NEED TO UPGRADE GOING WINTER STORM WRNGS TO
BLIZZARD WARNINGS IS PRIME FOCUS.
LATEST MODEL RUNS HAVE COME INTO GOOD AGREEMENT SHOWING SFC LO IN
MISSOURI THIS EVNG AT 00Z MOVING TO NEAR CHI AT 12Z WED BEFORE
REACHING NE LWR MI/LK HURON AT 00Z ON THU. CONSIDERING THE STRONG
JET STREAK ACCOMPANYING THE INCRSGLY NEGATIVELY TILTED SHRTWV
LIFTING OUT OF THE SW AS WELL AS THE RELATIVELY WARM WATERS OF THE
GREAT LKS THAT WOULD ENHANCE PRES FALLS...TENDED TOWARD THE SOMEWHAT
STRONGER NAM FOR FCST DETAILS ACCOMPANYING THIS IDEAL TRACK FOR
HEAVY SN ACRS UPR MI. VERY GOOD AGREEMENT BTWN THE NAM AND LOCAL
WRF-ARW RUN INCREASES CONFIDENCE IN THIS CHOICE OF MODEL/SOMEWHAT
DEEPER LO.
EXPECT WDSPRD SN TO ARRIVE SW-NE THIS EVNG WITH ARRIVAL OF DEEP LYR
QVECTOR CNVGC/UPR DVGC IN ADVANCE OF THE APRCHG SHRTWV/SFC LO. THE
SN WL TURN HEAVY AT TIMES OVERNGT...ESPECIALLY WHERE CYC UPSLOPE NE
FLOW ENHANCES SN AMTS IN THE FAVORED AREAS NEAR LK SUP. WITH H85
TEMPS IN THE -10C TO -12C RANGE...EXPECT QUITE A BIT OF LK ENHANCED
SN IN THESE AREAS AND ALSO NEAR THE BAY OF GREEN BAY. NAM AND LOCAL
WRF-ARW QPF HINT AT THIS LK ENHANCEMENT...WITH STORM TOTAL SN THRU
LATE WED AS HIGH AS 24 INCHES OVER THE HIER TERRAIN OVER THE FAR W
AND ACRS THE NCNTRL WHERE CYC NNE UPSLOPE FLOW IS MAXIMIZED. LARGER
SCALE SYNOPTIC SUPPORT FOR SN WL DIMINISH ON WED AFTN WITH EXIT OF
QVECTOR CNVGC...BUT UPSLOPE NLY FLOW WL CONTINUE THE HIER POPS NEAR
LK SUP. TENDED TO DIMINISH POPS OVER THE SCNTRL IN THE AFTN WITH
DOWNSLOPING FLOW/ CAD.
FCST SDNGS SHOW IMPRESSIVE UVV WITHIN PRIME SN GROWTH LYR...BUT
STRONG WINDS WL TEND TO MITIGATE SN GROWTH A BIT BY BREAKING UP THE
DENDRITES. BUT SMALLER FLAKES WL BE MORE EFFICIENT AT REDUCING THE
VSBY AND CAUSING BLSN. NAM FCST SDNGS SHOW RELATIVELY UNSTABLE LLVLS
WITH THE LO H85 TEMPS...WHICH WL ENHANCE MIXING OF STRONG 35 TO 45
KT H925 WINDS TO THE SFC...ESPECIALLY IN AREAS EXPOSED TO NE WINDS
NEAR LK SUP/BAY OF GREEN BAY. CONSIDERING THE POTENTIAL FOR STRONG
WINDS...HVY SN...AND LIKELIHOOD FOR REDUCED VSBY IN PLACES EXPOSED
TO THE NE WIND...OPTED TO UPGRADE WINTER STORM WARNING TO BLIZZARD
WARNING FOR KEWEENAW...BARAGA...MQT...AND MNM COUNTIES. ALSO THOUGHT
ABOUT ALGER...HOUGHTON...ONTONAGON...AND GOGEBIC COUNTIES...BUT HELD
OFF FOR NOW GIVEN SHELTERING OF MOST OF THOSE COUNTIES FM STRONGER
NE FLOW.
OTRW...ISSUED A LAKESHORE FLOOD STATEMENT FOR MOST AREAS ALONG LAKE
SUPERIOR WEST OF MUNISING WITH THE STRONG NNE WINDS CAUSING WAVES AS
HI AS 20 TO 25 FEET TO IMPACT THE SHORE. THESE WAVES MAY CAUSE SOME
MINOR FLOODING OF LOW LYING ROADS NEAR LAKE SUPERIOR AND SOME BEACH
EROSION AS WELL.
COORDINATED WITH GRB.
.LONG TERM /WEDNESDAY NIGHT THROUGH SUNDAY/...
WEDNESDAY NIGHT...FORECAST PERIOD BEGINS WITH STRONG WINTER STORM
CENTERED NEAR GEORGIAN BAY WITH A PRESSURE AROUND 975MB. DEEP/MOIST
CYCLONIC FLOW ON THE BACKSIDE OF THIS SYSTEM WILL WARRANT HEAVY
LAKE ENHANCED SNOWFALL...ESPECIALLY NEAR LAKE SUPERIOR. WINDS
HOWEVER WILL BE DIMINISHING INTO LATE WEDNESDAY NIGHT LIKELY
ENDING ANY BLIZZARD CONDITIONS...BUT BLOWING SNOW WILL STILL BE AN
ISSUE FOR M-28 EAST OF MARQUETTE INTO ALGER COUNTY WITH FAVORABLE
NORTH WIND DIRECTION. BY LATE WEDNESDAY NIGHT WINDS BACK QUICKLY
TO THE NORTHWEST...SHIFTING HIGHER POPS/SNOW TOTALS TO TRADITIONAL
NORTHWEST SNOW BELTS.
THURSDAY AND THURSDAY NIGHT...STRONG WINTER STORM IS NOW PROGRESSING
STEADILY TOWARD THE CANADIAN MARITIMES...THOUGH SNOW IS FAR FROM
DONE FOR WEST-NORTHWEST SNOW BELTS. FAIRLY COLD AIR REMAINS
ENTRENCHED ACROSS THE UPPER GREAT LAKES WITH 850MB TEMPERATURES
AROUND -21C. THROUGHOUT THE DAY ON THURSDAY PBL FLOW BACKS MORE TO
THE WEST SHIFTING BANDS SLIGHTLY NORTH...THOUGH MODERATE SNOW
ACCUMULATIONS WILL CONTINUE OVER THE KEWEENAW. IT/S NOT OUT OF THE
REALM OF POSSIBLY OF A DOMINANT BAND FORMING WITHIN THE SOUTHWEST
FLOW...IMPACTING NORTHERN KEWEENAW COUNTY...SIMILAR TO THIS PAST
WEEKEND.
FRIDAY THROUGH MID NEXT WEEK...WITH LOW PRESSURE NOW OVER HUDSON BAY
AND SURFACE RIDGING EXTENDING BACK FROM THE SOUTHEASTERN CONUS TO THE
NORTHWEST INTO THE SOUTHERN CANADIAN PRAIRIES...COLD AIR OVER THE
NORTHERN CANADIAN PRAIRIES HAS AN OPPORTUNITY TO SHIFT SOUTH UNDER
BROAD NORTHWESTERLY FLOW ALOFT. MEDIUM RANGE GUIDANCE CONTINUES TO
SHOW COLDEST AIR...-30C OR COLDER AT 850MB...REMAINING NORTH OF LAKE
SUPERIOR. WITH TROUGH PASSAGE SATURDAY NIGHT MAY HAVE TO CONSIDER
WIND CHILL ADVISORIES...ESPECIALLY IN THE WEST. LONG RANGE PATTERN
SUGGESTS A MORE PROGRESSIVE FLOW WITH ZONAL FLOW CONTINUING AT 500MB
FROM LATE THIS WEEKEND INTO NEXT WEEK. GUIDANCE ALSO HINTS AT A
SECOND INTRUSION OF COLD AIR...SUNDAY NIGHT INTO TUESDAY.
&&
.AVIATION /FOR THE 00Z TAF ISSUANCE/...
LOW PRES OVER WCNTRL IL WILL RAPIDLY INTENSIFY AS IT MOVES NE...
CROSSING THE GREAT LAKES REGION TODAY. ASSOCIATED SHIELD OF SNOW
WILL AFFECT KCMX/KSAW INTO THE AFTN WITH PERIODS OF MDT/HVY SNOW
UNDER FAVORABLE LAKE ENHANCEMENT CONDITIONS. SNOW WILL TRANSITION TO
LAKE EFFECT SHSN IN THE EVENING. EXPECT IFR CONDITIONS TO START THE
FCST TO TREND DOWN TO LIFR/VLIFR OVERNIGHT AND THRU THE DAY UNDER
MDT/OCCASIONALLY HVY SNOW WITH SIGNIFICANT BLSN DEVELOPING AS WINDS
GUST 30-40KT. NE TO N WIND DIRECTION WILL FAVOR STRONGEST
WINDS/HEAVIEST SNOW AT KSAW. AS WINDS BACK NW AND DIMINISH IN
THE EVENING...CONDITIONS WILL BEGIN TO IMPROVE AT KSAW. LAKE EFFECT
SHSN/WINDS/BLSN SHOULD MAINTAIN VLIFR CONDITIONS AT KCMX INTO THE
EVENING.
&&
.MARINE /FOR THE 4 PM LAKE SUPERIOR FORECAST ISSUANCE/...
NORTHEAST FLOW AROUND LOW PRESSURE MOVING FROM THE PLAINS TO NORTHERN
LOWER MI LATE ON WED...CONTINUED GOING GALE WARNINGS WITH UNSTABLE
COLD AIR OVER THE RELATIVELY WARM LAKE WATERS ENHANCING MIXING OF
STRONGER WINDS TO THE SFC. EXPECT GALE FORCE WINDS TO IMPACT LAKE
SUPERIOR INTO WEDNESDAY. ADDITIONAL GALE FORCE WINDS ARE POSSIBLE
AGAIN ON THURSDAY NIGHT. PLEASE SEE THE LATEST MARINE HAZARD
MESSAGE FOR FURTHER DETAILS.
&&
.MQT WATCHES/WARNINGS/ADVISORIES...
UPPER MICHIGAN...
WINTER STORM WARNING UNTIL 1 AM EST /MIDNIGHT CST/ THURSDAY
FOR MIZ002-003-009>011-013-014-084.
WINTER STORM WARNING FROM 1 AM WEDNESDAY TO 1 AM EST THURSDAY
FOR MIZ006-007-085.
BLIZZARD WARNING UNTIL 1 AM EST THURSDAY FOR MIZ001-004-005.
BLIZZARD WARNING UNTIL 6 PM CST WEDNESDAY FOR MIZ012.
LAKE SUPERIOR...
GALE WARNING FROM 1 AM WEDNESDAY TO 7 AM EST THURSDAY FOR
LSZ243>245-264>267.
GALE WARNING FROM 7 AM EST /6 AM CST/ TO 7 PM EST /6 PM CST/
WEDNESDAY FOR LSZ240>242-246>251.
GALE WARNING FROM 1 AM EST /MIDNIGHT CST/ TO 10 PM EST /9 PM
CST/ WEDNESDAY FOR LSZ162.
GALE WARNING FROM 1 AM WEDNESDAY TO 4 AM EST THURSDAY FOR LSZ263.
LAKE MICHIGAN...
GALE WARNING FROM 1 AM WEDNESDAY TO 1 AM EST THURSDAY FOR LMZ221-
248-250.
&&
$$
UPDATE...ROLFSON
SHORT TERM...KC
LONG TERM....PEARSON
AVIATION...ROLFSON
MARINE...KC
