Winter Storm in Michigan, March 8, 2002

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE MARQUETTE MI
445 AM EST FRI MAR 8 2002

A LOT TO CONSIDER THIS MORNING FROM ENDING CURRENT BOUT OF WINTRY
PRECIP TO HEADLINES ASSOCIATED WITH MAIN LOW LATE TONIGHT THRU SAT
NIGHT. IN ADDITION TO SNOW ON BACKSIDE OF LOW...DAMAGING WINDS
CERTAINLY A POSSIBILITY SAT AFTN/NIGHT.

WV IMAGERY SHOWS STRONG SHORTWAVE APPROACHING 4 CORNERS AREA. THIS
WILL BE SYSTEM THAT LEADS TO STRONG CYCLOGENESIS FROM PLAINS ACROSS
UPPER LAKES. LEAD SHORTWAVE IS STREAKING NE THRU UPPER MIDWEST ATTM.
VERY STRONG WAA/ISENTROPIC LIFT AHEAD OF SHORTWAVE HAS GENERATED
CONVECTIVE PRECIP ACROSS WRN LAKES THIS MORNING WITH A VERY
IMPRESSIVE AMOUNT OF CG LIGHTNING ACROSS WI. LOW-LEVEL JET WAS
UPWARDS OF 55KTS PER PROFILERS DURING THE NIGHT.

00Z MODEL RUNS ARE VERY SIMILAR IN HANDLING OF STRONG SHORTWAVE
GOING NEGATIVE TILT AS IT LIFTS THRU GREAT LAKES SAT. SFC LOW TRACKS
ARE SIMILAR AS ARE THERMAL FIELDS. ONLY MAJOR DIFFERENCE IS THAT ETA
IS MORE INTENSE WITH DEEPENING OF SFC LOW...MAKING IT A BOMB AS IT
MOVES FROM WI TO JAMES BAY. INTENSE CAA AND STRENGTH OF WIND FIELDS
IT DEVELOPS WOULD BRING HIGH WINDS TO ALL OF THE FA...AND ESPECIALLY
KEWEENAW COULD SEE DAMAGING WINDS.

MODELS INDICATE THAT GOING ZONE FCST HAS A VERY GOOD HANDLE ON
DETAILS FOR TODAY. LEAD SHORTWAVE MOVES NE OF UPPER MI THIS MORNING
WITH 850MB WARM FRONT THEN LIFTING N THRU FA. IMPRESSIVE 850-700MB
FRONTOGENESIS AND ISENTROPIC ASCENT EXIT THIS MORNING...AND ALL THE
MODELS SHOW A POCKET OF 700MB RH LESS THAN 40PCT THEN LIFTING NE
ACROSS FA. NEAR SATURATION BELOW DRY LAYER SUPPORTS THE IDEA OF SOME
PATCHY -FZDZ/DZ IN THE WAKE OF MAIN PRECIP AREA THIS MORNING. WITH
SFC WARM FRONT JUST S OF FA TODAY...AREAS OF FOG SHOULD ALSO DEVELOP
(ESPECIALLY IN HIGHER TERRAIN LOCATIONS) AS WARM/MOIST AIR LIFTS N
OVER SNOWPACK.

TONIGHT...SHORTWAVE MOVES INTO CNTRL PLAINS AND BEGINS TO TAKE ON
NEGATIVE TILT SAT MORNING. AS A RESULT...CYCLOGENESIS TAKES PLACE IN
KS WITH LOW LIFTING TO NCNTRL WI BY 12Z SAT. SFC LOW GOES ON TO
DEEPEN QUITE RAPIDLY SAT AS IT LIFTS ACROSS CNTRL UPPER MI/ERN LK
SUPERIOR...REACHING JAMES BAY LATE SAT EVENING. IN RESPONSE TO
SHORTWAVE MOVING OUT INTO PLAINS TONIGHT...LOW-LEVEL JET INTO WRN
LAKES CRANKS TO 55KTS OR BETTER BY 06Z. WITH THAT...ANOTHER ROUND OF
ISENTROPIC ASCENT SPREADS ACROSS FA BY LATE EVENING...AND MODELS IN
EXCELLENT AGREEMENT SHOWING PRECIP ACROSS FA BY 06Z. AS FOR
P-TYPE...ETA/NGM/AVN SHOW 850MB TEMPS 0 TO 1C ACROSS FAR WRN FA AT
06Z RANGING TO 6C OR BETTER OVER SE FA. AT WARMEST TIME...1000-850MB
THICKNESS ON ETA/NGM ARE 1305M OR LWR ROUGHLY W OF A LINE FROM IRON
RIVER TO LANSE. WARMER AVN SHOWS 1305M LINE AS FAR W AS KIWD BY 12Z
SAT. EXAMINATION OF ETA FCST SOUNDINGS INDICATE FZRA AS DOMINANT
PRECIP TYPE TONIGHT OVER KEWEENAW WITH TEMPS +1 TO +3C IN ROUGHLY A
2KFT LAYER CENTERED AROUND 4KFT. SOUNDING FOR KIWD SUPPORTIVE OF
SNOW/PL MIX WITH A 2KFT LAYER OF 0 TO +1C. WITH ALL THE MODELS
SHOWING 850MB LOW MOVING OVER FAR WRN FA/WRN LK SUPERIOR...MAIN HVY
SNOW THREAT WILL BE W FA. WILL LEAVE WATCH GOING FOR LATE TONIGHT
BARAGA/IRON WWD...BUT MORE FOR THE POTENTIAL OF ACCUMULATIONS OF
FZRA/IP WHICH WILL TRANSITION BACK TO SNOW SAT.

HAVE SOME CONCERN OVER NCNTRL FA OF ICE ACCUMULATIONS FOR A WHILE
TONIGHT. FWC/ETA 2M TEMPS SUGGEST TEMPS WILL REMAIN BLO FREEZING
DURING INITIAL PERIOD OF PRECIP TONIGHT WHEN SOUNDINGS SUPPORT
LIQUID PRECIP FALLING TO SFC. HAVE HARD TIME SEEING TEMPS STAYING
BLO FREEZING FOR VERY LONG GIVEN PRESENCE OF SUCH STRONG WAA
TONIGHT. WILL NOT ISSUE ANY HEADLINES FOR FZRA ATTM. SFC WARMING
THIS AFTN WILL BE A CRITICAL FACTOR IN DURATION OF FZRA TONIGHT.
OTHERWISE...EXPECT RAIN TO DOMINATE OVER ERN 2/3RDS OF FA TONIGHT
WITH STEADY/SLOWING RISING TEMPS.

AS SFC LOW PASSES N OF LK SAT AFTN...A FLASH FREEZE FOLLOWS IN AN
INTENSE CAA REGIME. 850MB TEMPS FALL UPWARDS OF 25C BTWN 12Z SAT AND
00Z SUN...AND RANGE FROM ABOUT -16C OVER ERN FA TO -19C OVER WRN FA
BY 00Z. BACKWASH -SHSN WILL REPLACE MORNING RAIN OVER CNTRL/ERN FA.
ETA SHOWS WINDS INCREASING TO AROUND 60KTS IN THE 2K-4KFT LAYER
ABOUT 6-9HRS AFTER LOW PASSES. OBVIOUSLY...INTENSE CAA AND
DYNAMIC/STRENGTHENING SYSTEM MAKES MIXING OF STRONG WINDS TO SFC A
REAL CONCERN...ESPECIALLY WHEN FCST SOUNDING EXHIBITS DRY ADIABATIC
PROFILE TO 800MB. ETA IS THE OUTLIER IN STRENGTH OF DEEPENING LOW...
SO WILL NOT BUY INTO IT COMPLETELY. EVEN THE WEAKER AVN/NGM SHOW
850MB WIND INCREASING TO 50KTS LATE AFTN/EVENING. BIGGEST CONCERN
FOR HIGH WINDS WILL BE OVER THE KEWEENAW AS WNW FLOW IS ALWAYS A BIG
HITTER THERE. APPEARS THERE IS A VERY GOOD POSSIBILITY OF HIGH WIND
WRNING CRITERIA BEING MET (40MPH OR GREATER SUSTAINED). RATHER THAN
DOUBLE HEADLINE EVENT ATTM...WILL STRONGLY WORD WINTER STORM WATCH
STATEMENT AND ZONES WITH HIGH WIND POTENTIAL. STORM FORCE WINDS A
STRONG POSSIBILITY ON LK SUPERIOR.

WITH SUCH STRONG WINDS...LK ENHANCED EVENT TRANSITIONING TO PURE LK
EFFECT SHOULD NOT BE AS SIGNIFICANT AS IT COULD BE WITH EXPECTED
EXTREME/DEEP INSTABILITY. RESIDENCE TIME WILL BE DRAMATICALLY
SHORTENED...AND OVER THE KEWEENAW...OROGRAPHIC ENHANCEMENT WILL BE
DISPLACED PASSED THE PENINSULA. BEST SNOW MAY ACTUALLY FALL IN
BARAGA/NRN IRON AND MAYBE AS FAR E AS MARQUETTE COUNTY.
NONETHELESS...WHERE ANY DECENT SNOW FALLS IT WILL BE WHIPPED INTO
BLIZZARD CONDITIONS. SO WATCH REMAINS JUSTIFIED FOR SAT BARAGA/IRON
WWD. OVER ALGER/LUCE...THOUGHT ABOUT A WATCH FOR POTENTIAL HVY LK
EFFECT/LK ENHANCED SNOW LATE SAT...BUT MODELS SHOW ALMOST A DUE WRLY
FLOW OVER SERN LK SUPERIOR...MINIMIZING ANY POTENTIAL OF LK
CONTRIBUTION.

COORD WITH GRB/YQT...THANKS.

.MQT...WINTER STORM WARNING THIS MORNING MIZ001>006-009-010.
       WINTER WEATHER ADVISORY THIS MORNING MIZ007-011.
       ICE STORM WARNING MIZ012>014.
       WINTER STORM WATCH LATE TONIGHT-SAT NIGHT MIZ001>004-009-010.
       GALE WRNG LK SUPERIOR.

ROLFSON