000 
FXUS63 KMQT 011058
AFDMQT

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE MARQUETTE MI
530 AM EST THU FEB 1 2001

00Z RAOBS AND LATEST WV LOOP/RUC ANAL SHOW DEEPENING UPR TROF AXIS 
NR INL WITH 120KT H3 JET MAX IN NRN PLAINS DIGGING S AND 
INTENSIFYING UPR TROF. H5 TEMPS IN -35 TO -40 RANGE UNDER TROF. SVRL 
SHRTWVS NOTED ROTATING ARND THIS FEATURE...THE FIRST OF THESE NOW 
ROTATING INTO WRN LK SUP. AT THE SFC...PERSISTENT TROF STRETCHES FM 
MN-CAN BORDER ACRS CNTRL LK SUP TO JUST N OF ANJ. COLD FNT 
ASSOCIATED WITH WRN LK SUP SHRTWV APRCHG ASX AT 09Z..SFC TEMPS FALL 
OFF TO BLO ZERO OVR MN. SOME LGT SN OBSVD ALG AND AHD OF 
SHRTWV/BNDRY...BUT 00Z GRB SDNG SHOWS DRY AIRMASS IN PLACE (PW 0.18 
INCHES). SO PCPN INTENSITY LIMITED DESPITE VIGOROUS H85-5 QVECTOR 
CNVGC. RAOBS TO W DEPICT A MORE MOIST AIRMASS UNDER UPR TROF. 00Z 
INL SNDG INDICATES A NR SATURATED AIRMASS UP TO H65 WITH NR MOIST 
ADIABATIC LAPSE RATE. MUCH DRIER AIR NOTED TO N IN ONTARIO WITH SFC 
DWPTS BLO -10F.

FCST CONCERNS THIS PACKAGE ARE NMRS...INCLUDING SN AMTS/HEADLINES 
AND WND/TEMPS. MODELS HAVE CONTD TREND TO BE SLOWER MOVG COLD 
AIRMASS/UPR TROF AXIS INTO NW GRT LKS AND SHIFTING POSITION OF LO 
PRES THAT DVLPS ALG TROF ACRS CNTRL LK SUP AHD OF THIS TROF FARTHER 
N...WHICH IS CONSISTENT WITH DEEPENING OF TROF AXIS TO W. FOLLOWED 
06Z ETA GUIDANCE MOST CLOSELY AS THIS MODEL APPEARS TO HAVE GOOD 
HANDLE ON THIS TREND.

FOR TDAY...WRN LK SUP SHRTWV PROGGED TO SLIDE ENEWD THRU CWA BY THIS 
AFTN WITH SFC COLD FNT NOW APRCHG ASX REACHING ERN ZNS LATE. AT SAME 
TIME...SFC LO DVLPS OVR CNTRL LK SUP AS H7 LO MOVES FM IWD AT 18Z TO 
MQT BY 00Z. THIS TRACK SUGS ONLY ONT/THE KEWEENAW PENINSULA WL SEE 
ANY UPR DYNAMICS/LK ENHANCEMENT WITH AXIS OF HIER UVV ACRS 
KEWEENAW.  AS SFC LO SHIFTS INTO CNTRL LK SUP... LLVL FLOW TURNS 
MORE NLY THERE... WITH NR UNIDIRECTIONAL NLY FLOW FOLLOWING PASSAGE 
OF SHARP SFC TROF S. LES CHART SUGS UP TO 8"/6 HRS WITH ABSENCE OF 
INVRN ACCOMPANYING H7-5 THERMAL TROF/MSTR AXIS ENHANCING 
INSTABILITY. WENT WITH WRNG FOR THIS AFTN/LATE TDAY IN PLACES ACRS W 
THAT WL SEE TROF PASSAGE... ROUGHLY NW OF L'ANSE TO MARENISCO. 
INCRSG PRES GRADIENT WITH BLYR WNDS UP TO 30 KTS ACCOMPANYING COLD 
AIR INFLOW WL ALSO CAUSE CONSIDERABLE BLSN AS WELL BEHIND TROF. REST 
OF CWA WL SEE A MORE WLY FLOW WITH NO OPPORTUNITY FOR LK MOISTENING 
ACCOMPANYING FAIRLY WEAK CNVGC WITH SFC COLD FROPA. SFC OBS TO W ALG 
BNDRY SUG ACCUMS WL BE ON THE LGT SIDE...LESS THAN AN INCH. XPCT 
TEMPS OVR SW INTERIOR ZNS TO FALL OFF DURG DAY BEHIND THIS FNT GIVEN 
TEMPS OBSVD OVR MN ATTM.

JET MAX EMERGING ON E SIDE OF UPR TROF WL DRAG TROF AXIS EWD ACRS 
CWA TNGT. AS SFC LO MOVES FM SCNTRL LK SUP THIS EVNG TO LK HURON BY 
12Z FRI...H7 LO TENDS TO SHEAR OUT WITH WND MAX ON ERN SIDE OF UPR 
TROF. AS A RESULT...SFC TROF/CNVGC AND MID LVL UVV ALSO PROGGED TO 
WEAKEN. SO ACCOMPANYING PCPN WL TEND TO DEGENERATE INTO PURE LES 
WITH INVRN HGT FALLING LATE ACCOMPANYING RISE IN UPR HGTS. STILL... 
LES CHART SUGS UP TO 10 INCHES OVRNGT IN AREAS FVRD BY MORE NLY 
FLOW...ONT/GOGEBIC ZNS. BUT CUT THESE AMTS A BIT OUT W TO TAKE INTO 
ACCOUNT INFLUX OF DRYER AIR AND SHIFTING WNDS OVRNGT. HEDGED BTWN 
WRNG/ADVY FOR BARAGA/MQT COUNTY...BUT SINCE MODELS HAVE TRENDED 
SLOWER DROPPING IN COLDER AIR WITH SFC LO TRACKING MORE TO N AND LTL 
IN THE WAY OF SYNOPTIC UVV...DECIDED TO GO WITH JUST ADVY HERE. ALSO 
OPTED NOT TO GO WITH HEADLINE FOR ALGER COUNTY DUE TO THIS SAME 
TREND EVEN THOUGH FVRBL NNWLY WND DVLPS LATE TNGT. LUCE COUNTY WL 
SEE LTL IF ANY LK MOISTENING WITH MORE NLY FLOW. 06Z ETA CONTS 00Z 
RUN TREND TO BRING 30-35KT NLY WND MAX IN INCRSG PRES GRAD/CYC 
FLOW...SO XPCT BLSN TO BE A SGNFT PROBLEM. BLSN MENTIONED IN 
HEADLINES. LACK OF LLVL CNVGC/ UPR DYNAMICS ACRS S SUG JUST SCT 
-SHSN THERE. WND WITH INCRSG PRES GRADIENT PROBABLY MOST SGNFT 
INFLUENCE ACRS S.

AS UPR HGTS CONT RISING FRI WITH SFC RDG AXIS MOVG INTO CWA DURG 
AFTN...XPCT LES/BLSN TO DIMINISH W-E. PERSISTENT H95 CNVGC AND FVRBL 
NNWLY FLOW IN THE MRNG WILL KEEP SGNFT ENUF LES GOING TO MAINTAIN 
ADVY ACRS NCNTRL INTO EARLY FRI.

COORDINATEDi WITH DLH/GRB.

.MQT...WINTER STORM WRNG MIZ001-003 THIS AFTN AND TNGT.
       WINTER STORM WRNG MIZ002-009 LATE TDAY AND TNGT.
       SN/BLSN ADVY LATE TNGT/EARLY FRI MIZ004-005.
      
KC