Flooding in Michigan, March 5 to 7, 2004

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE GAYLORD MI
1028 PM EST THU MAR 4 2004

.SHORT TERM...ONSET OF PRECIP IS OCCURRING A BIT EARLIER THAN
EXPECTED... WITH RAIN EDGING INTO THE SOUTHERN ZONES AT 02Z.
ONE WONDERS IF WARM ADVECTION WILL ALSO BE FASTER THAN ANTICIPATED.
IF NOT...MORE OF THE PRECIP IN THIS INITIAL SURGE WILL BE WINTRY AS
OPPOSED TO RAIN. THIS IS THE CLEAR DILEMMA OF THE NIGHT.

THERE ARE MANY HEADACHES TO CONTEND WITH. ALL AREA 00Z SOUNDINGS
(APX/DTX/GRB) ARE AROUND 2C COOLER BELOW 750 THAN THE 18Z ETA
INDICATED. NOTE THAT EVAP COOLING WAS NOT A PLAYER AS FAR NORTH AS
APX/GRB BY 00Z...THUS CAN/T BLAME THE PRECIP FOR THIS ONE...THE ETA
THERMAL FIELDS WERE JUST BAD. THE 00Z RUC IS MUCH BETTER INITIALLY
THERMALLY...THOUGH IT TOO DOES NOT BRING PRECIP NORTH FAST ENOUGH.
NEXT COMPLICATION...DESPITE STARTING COOLER (AND CORRECTLY SO) THE
RUC ENDS UP WARMER THAN THE ETA ALOFT BY 09Z. THIS APPEARS TO BE
RELATED TO THE THERMAL RIDGE NOSING INTO CENTRAL/SOUTHERN MO...WHERE
AGAIN THE RUC LINES UP BETTER WITH THE THE 00Z RAOBS VS THE ETA
WHICH IS TOO COLD. SO I WILL LEAN HEAVILY TOWARD THE RUC THERMAL
FIELDS ALOFT.

WILL MENTION MIXED PRECIP FURTHER SOUTH IN NORTHERN LOWER. CURRENT
SURFACE OBS SUGGEST THAT TVC/HTL/CAD/OSC COULD SEE A MIX FOR THE
NEXT 3-4 HOURS BEFORE SOUNDINGS WARM DRAMATICALLY AFTER 06Z. THE
EXTREME SW AND SE CORNERS (MBL/GLADWIN/STANDISH) SHOULD STAY
SNOW-FREE. WILL ALSO NOT ALLOW RAIN TO MIX IN QUITE AS FAR NORTH
OVERNIGHT...THOUGH THIS ADJUSTMENT WILL BE MINOR.

MY MAIN INTERNAL DEBATE TONIGHT HAS BEEN WHETHER...WITH MORE PRECIP
SOONER...TO UPGRADE EMMET/CHEBOYGAN TO A WINTER STORM WARNING. THE
HEAVIER QPF FORECASTS FROM THE ETA ARE WORKING OUT NICELY UPSTREAM
(WIDEPSREAD 3 HOUR PRECIP TOTALS OF A THIRD TO A HALF INCH FROM
NORTHERN IL TO FAR SW LOWER MI). SO AM THINKING THAT NORTH OF A LINE
FROM HARBOR SPRINGS TO THE NE CORNER OF CHEBOYGAN CO...4 TO 7 INCHES
OF SNOW WILL FALL BEFORE THE CHANGE TO RAIN FRIDAY MORNING. GIVEN
THIS WILL BE A HEAVY WET AND INTENSE SNOW THAT WILL BE ACCOMPANIED
BY A BRISK EAST WIND (ESPECIALLY BRISK IN THE STRAITS)...I WILL
UPGRADE THOSE TWO COUNTIES. WILL ALSO TWEAK SE PARTS OF UPPER MI FOR
A BIT MORE IN THE WAY OF SNOW. ALSO TOYED WITH MOVING ADVISORY
ANOTHER TIER OF COUNTIES SOUTH...BUT THINK THE SNOW THERE WILL
INITIALLY TEND TO MELT AS IT FALLS...WHICH WILL KEEP ACCUMS DOWN.

ZOLTOWSKI

&&

.PREV DISCUSSION ISSUED 355 PM THU MAR 4...

LONG TERM...IMPACT OF LATE WINTER STORM CONTINUES TO BE PRIMARY
FORECAST CONCERN FOR FRIDAY. A BROAD RANGE OF HAZARDS ARE
EXPECTED...WITH HEAVY SNOW IN ERN UPPER...RAIN/SNOWMELT-INDUCED
FLOODING ACROSS NRN LOWER...AND POSSIBLE STRONG/SEVERE THUNDERSTORMS.

12Z MODEL RUNS TRACK SURFACE LOW FROM ERN IA FRI MORNING...ENE
ACROSS SRN WI DURING THE MORNING...AND INTO LAKE HURON FRI EVENING.
ETA HAS BEEN REASONABLY CONSISTENT WITH IT/S TRACK ACROSS FAR NRN
LOWER. THE GFS HAS TRENDED A BIT SWD WITH IT/S TRACK -- WITH THE 12Z
RUN NOW MOVING LOW ACROSS CENTRAL LOWER. OBVIOUSLY...THIS WILL HAVE
LARGE IMPACT ON RAIN/SNOW LINE. BOTH MODELS INDICATE HEAVY SNOW
FALLING EARLY FRI ACROSS ERN UPPER AND EXTREME TIP OF NRN LOWER.
STRONG WAA AHEAD OF LOW WILL BATTLE ADIABATIC COOLING AND
MELTING-INDUCED COOLING TO DETERMINE PRECISE RAIN/SNOW LINE. ETA
MODEL SOUNDINGS SUGGEST THAT SNOW WILL CHANGE TO FREEZING RAIN OR
RAIN BY MID MORNING NEAR THE STRAITS...AS NOSE OF +3C AIR DEVELOPS
NEAR 800 MB. GIVEN THE ETA/S RECENT COLD BIAS IN THE BOUNDARY LAYER
AND FACT THAT THERE WON/T BE APPRECIABLE EVAPORATIVE COOLING (GIVEN
LACK OF DRY AIR NEAR SURFACE) FEEL THAT THERE WILL BE A SHARP
RAIN/SNOW LINE...WITHOUT A SIGNIFICANT AMOUNT SLEET OR FREEZING
RAIN. FORECAST/GRIDS WILL REFLECT THIS ACCORDINGLY. WILL CONTINUE
WINTER STORM WARNING THROUGH THE DAY FOR CHIPPEWA/MACKINAC COUNTIES.
EXPECTED QPF...EVEN WITH A 10:1 SNOW TO LIQUID RATIO...SUPPORTS 6 TO
8 INCHES DURING THE DAY (PRIMARILY BEFORE NOON). NW PORTIONS OF
CHIPPEWA/MACKINAC COUNTY (W OF I-75) EXPECTED TO SEE BULK OF SNOW.
HOWEVER...IF SWD GFS STORM TRACK VERIFIES...MUCH MORE MAY FALL
ACROSS ALL OF WARNING AREA.

FARTHER SOUTH...STRONG INFLOW IN ADVANCE OF SURFACE LOW WILL ADVECT
PLENTY OF WARMTH/MOISTURE INTO LOWER MI. WARM FRONT WILL LIFT NWD TO
EXTEND ROUGHLY FROM TVC TO APN BY EARLY AFTERNOON. EXPECT WIDESPREAD
RAIN N OF WARM FRONT EARLY...WITH PERHAPS SOME ELEVATED CONVECTION.
THINGS MAY THEN GET MORE INTERESTING BY MIDDAY AS WARM FRONT LIFTS N
AND MID LEVEL DRY PUNCH MOVES ACROSS LOWER MI. THOUGH MODEL
SOUNDINGS INDICATE THAT CONVECTION WILL REMAIN ELEVATED...A MODIFIED
18Z MODEL SOUNDING ACROSS S CENTRAL PARTS OF FORECAST AREA YIELDS
ABOUT 700 J/KG CAPE (PARCEL LIFTED FROM 900 MB) WITH WBZ/S NEAR 7
KFT. UNIDIRECTIONAL WIND PROFILE AND DEEP LAYER SHEAR VALUES OF
50-60 KTS POINTS TO POSSIBLY BOW ECHOS. POTENTIAL WILL EXIST FOR
BOTH HIGH WINDS AND MARGINALLY SEVERE HAIL DURING THE DAY...MAINLY
ACROSS S/SE PARTS OF FORECAST AREA.

LASTLY...WILL ISSUE FLOOD WATCH FOR ALL OF NRN LOWER MI FOR FRIDAY.
WITH PLENTY OF SNOW STILL ON THE GROUND...AREA RIVERS ON THE RISE...
AND UP TO AN INCH OF RAINFALL BETWEEN LATE TONIGHT AND FRIDAY
EXPECTED.

FRIDAY NIGHT...COLDER AIR WILL WRAP IN BEHIND DEPARTING SYSTEM
FRIDAY EVENING...AND GRADUALLY CHANGE LINGERING RAIN SHOWERS BACK
OVER THE SNOW. ANOTHER INCH OR SO OF SNOW MAY ACCUMULATE ACROSS ERN
UPPER...WITH LESSER AMOUNTS ELSEWHERE.

SATURDAY...LINGERING MOISTURE AND CYCLONIC FLOW WILL KEEP SKIES
MOSTLY CLOUDY. ALSO EXPECT SCATTERED LIGHT SNOW SHOWERS. RIDGE AXIS
WILL APPROACH BY SATURDAY EVENING BEFORE NEXT SYSTEM COMES IN FOR
LATE SAT NIGHT AND SUN.

SUNDAY THROUGH THURSDAY...TROUGHING ALOFT WILL REMAIN IN PLACE INTO
THE EARLY PART OF NEXT WEEK. THIS WILL HELP TO MAINTAIN UNSETTLED
WEATHER ACROSS THE REGION. INDIVIDUAL SHORT WAVES THAT WILL HELP TO
HOLD TROUGH IN PLACE VERY DIFFICULT TO TIME...AND MODELS SHOW LITTLE
CONSENSUS IN THIS RESPECT. IT DOES APPEAR (CONSISTENT WITH GOING
FORECAST) THAT STRONGEST SHORT WAVE WILL MOVE IN BY SUNDAY...AND
PROVIDE REGION WITH A QUICK SHOT OF SNOW BEGINNING LATE SAT NIGHT
INTO SUN (THOUGH LATEST MODEL RUNS POINT TO LOW PASSING A BIT
FARTHER SW). A SERIES OF WEAKER SHORT WAVES WILL THEN DROP IN FROM
THE NW...AND WILL CONSEQUENTLY MAINTAIN A RISK FOR SNOW SHOWERS OR
FLURRIES MON THRU WED -- THOUGH NOTHING SIGNIFICANT EXPECTED. SOME
INDICATIONS THAT UPPER TROUGH WILL LIFT NE BY THU...ALLOWING A MORE
ZONAL FLOW ALOFT TO SET UP. IN SPITE OF BUILDING HEIGHTS...
ASSOCIATED WAA MAY SUPPORT A RAIN/SNOW MIX THU. TEMPERATURES WILL
GENERALLY HOLD CLOSE TO NORMAL THROUGH THE PERIOD...WITH HIGHS
AROUND 30 IN ERN UPPER...AND IN THE 30S TO NEAR 40 ACROSS NRN LOWER.

SMITH

&&

.APX...WATCHES/WARNINGS/ADVISORIES...
       WINTER STORM WARNING...LATE TONIGHT THRU FRIDAY...MIZ008-015.
       WINTER STORM WARNING...LATE TONIGHT THRU NOON FRIDAY...
        MIZ016-017.
       WINTER WEATHER ADVISORY...LATE TONIGHT...MIZ018>024.
       FLOOD WATCH...FRIDAY...ALL OF NRN LOWER MI.

&&

HAZARDOUS WEATHER OUTLOOK...CORRECTED
NATIONAL WEATHER SERVICE GAYLORD MI
550 AM EST FRI MAR 5 2004

MIZ008-015>036-041-042-061200-
ALCONA-ALPENA-ANTRIM-ARENAC-BENZIE-CHARLEVOIX-CHEBOYGAN-CHIPPEWA-
CRAWFORD-EMMET-GLADWIN-GRAND TRAVERSE-IOSCO-KALKASKA-LEELANAU-
MACKINAC-MANISTEE-MISSAUKEE-MONTMORENCY-OGEMAW-OSCODA-OTSEGO-
PRESQUE ISLE-ROSCOMMON-WEXFORD-
550 AM EST FRI MAR 5 2004

THIS HAZARDOUS WEATHER OUTLOOK IS FOR NORTHERN LOWER AND EASTERN
UPPER MICHIGAN.

.DAY ONE...TODAY AND TONIGHT

SNOW...HEAVY AT TIMES IN EASTERN UPPER MICHIGAN...WILL FALL THROUGH
THE DAY. MORNING SNOW...RAIN AND FREEZING RAIN WILL FALL ACROSS
NORTHERN LOWER MICHIGAN...THEN CHANGE TO RAIN IN THE AFTERNOON. THE
PRECIPITATION WILL CREATE HAZARDOUS DRIVING CONDITIONS FOR THE
MORNING COMMUTE. SEE ONGOING WATCHES...WARNINGS...OR ADVISORIES FOR
ADDITIONAL DETAILS.

IN ADDITION...RAINFALL AMOUNTS OF GREATER THAN ONE INCH ARE FORECAST
ACROSS NORTHERN LOWER MICHIGAN BY EARLY THIS EVENING. THIS
ADDITIONAL RAINFALL...COMBINED WITH THE RAIN AND SNOWMELT FROM
EARLIER THIS WEEK...WILL RESULT IN ADDITIONAL RISES IN AREA RIVERS
AND COULD LEAD TO FLOODING.

.DAYS TWO THROUGH SEVEN...SATURDAY THROUGH THURSDAY

FINALLY...ACCUMULATING SNOWFALL IS POSSIBLE LATE SATURDAY NIGHT INTO
SUNDAY.

.SPOTTER INFORMATION STATEMENT...

SPOTTERS PLEASE RELAY YOUR SNOWFALL REPORTS TO THE NATIONAL WEATHER
SERVICE. SPOTTER ACTIVATION MAY BE REQUIRED ON FRIDAY.
DISPATCHERS...PLEASE NOTIFY YOUR EMERGENCY MANAGERS IMMEDIATELY.
&&

MORE INFORMATION MAY BE OBTAINED AT THE FOLLOWING URL:
HTTP://WWW.CRH.NOAA.GOV/APX (ALL LOWER CASE)

SMD