FXUS63 KDLH 121800 AAB
AFDDLH
AREA FORECAST DISCUSSION...UPDATED
NATIONAL WEATHER SERVICE DULUTH MN
1200 PM CST FRI MAR 12 2010
.AVIATION...VERY LARGE CIRCULATION... ASSOCIATED WITH INTENSE MID LVL
LOW OVER CTRL PLAINS...WILL KEEP A LAYER OF DEEP MOISTURE OVER TAF
SITES. PERIODS OF PRECIP WILL AFFECT CWA AS INDIVIDUAL DISTURBANCES
MOVE AROUND MAIN SYSTEM. IFR ACROSS SRN SITES TODAY AND THEN
LOWERING TO LIFR/VLIFR OVERNIGHT. KINL/KHIB WILL HAVE BEST CHANCE
OF DECENT CONDITIONS WITH MVFR/VFR BASES TODAY...THEN LOWERING TO
IFR OVERNIGHT.
&&
.PREV DISCUSSION... /ISSUED 1103 AM CST FRI MAR 12 2010/
UPDATE...
INCREASED WINDS ALONG THE SHORE...ESPECIALLY THE NORTH SHORE
TODAY. MADE MINOR CHANGES...INCLUDING CHILLING THE SHORE DURING
THE DAYTIME.
DISCUSSION...
HIGH DEW POINTS ARE BEING ADVECTED BACK AHEAD OF A TROUGH FROM
OVER PINE COUNTY THROUGH MKE TO SDF. WET DEW POINTS HAVE ADVECTED
NORTHWARD AND NORTHWESTWARD AHEAD OF THE TROUGH. A MESO- LOW HAS
FORMED AT THE NORTHWEST TIP AND RAPIDLY DEEPENED...THE VERY SHORT-
TERM RUC IS THE ONLY MODEL TO PICK THIS UP. ANY THUNDER THAT WOULD
DEVELOP ALONG THE TROUGH WOULD REMAIN SOUTHEAST OF OUR AREA.
HOWEVER...THE MESO-LOW HAS FORMED A TIGHT GRADIENT OVER THE TWIN
PORTS AREA AND THE GRADIENT IS WORKING ITS WAY UP THE NORTH SHORE.
SO...WE INCREASED WINDS...ESPECIALLY WHERE TOPOGRAPHIC FUNNELING
TAKES PLACE...THROUGH THIS AFTERNOON...THE LOW IS EXPECTED TO
MOVE SOUTHWEST AND WEAKEN LATER THIS AFTERNOON. WITH AN ONSHORE
FLOW THROUGH THE WEEKEND...WE LOWERED AFTERNOON TEMPERATURES ALONG
THE COAST A LITTLE. THE WIND IS MITIGATING FOG RESULTING FROM SNOW
MELT...AND RATHER MAINTAINING A LOW CEILING. FEW IF ANY OTHER
CHANGES WERE NEEDED.
PREV DISCUSSION... /ISSUED 557 AM CST FRI MAR 12 2010/
UPDATE...12Z TAF DISCUSSION...
AVIATION...EXPECT IFR/LIFR CONDITIONS TO PERSIST THROUGH MOST OF THE TAF
PERIOD. THERE MAY ALSO BE MVFR AT TIMES IN PRECIP...WITH EVEN VFR
ALONG THE NORTHERN AND EASTERN NORTH SHORE FROM BFW TO GNA.
THE MAIN FORCING WITH THE NEXT WAVE OF PRECIPITATION IS EXPECTED TO
CONTINUE DURING THE 12Z-18Z TIME (6AM - NOON)...AND GENERALLY
FOCUSED ALONG A LINE FROM KBRD...TO KDLH...TO KHYR. THIS AREA IS WHERE
A DECENT BAND OF 925-700 FRONTOGENESIS IS ROTATING WESTWARD ACCOMPANIED BY
AN UPPER LEVEL DISTURBANCE SWINGING WESTWARD AROUND THE PARENT
UPPER LEVEL LOW. THIS UPPER LOW WILL SINK SOUTHWARD DURING THE
DAY...AND WILL THUS KEEP THE HEAVIER PRECIPITATION AWAY FROM
KINL...WITH KHIB ON THE NORTHERN FRINGE...AND FRONTOGENESIS WILL
WEAKEN WITH THIS NEXT BATCH OF RAIN.
NO LIGHTNING HAS BEEN DETECTED IN ANY OF THE SHOWER ACTIVITY IN
THE LAST FEW HOURS EXCEPT IN CENTRAL WISCONSIN...ASSOCIATED WITH
ANOTHER BAND OF SHOWERS/THUNDERSTORMS AND YET ANOTHER DISTURBANCE
MOVING NORTHWARD. LITTLE TO NONE IS EXPECTED ATTM ACROSS THE
NORTHLAND...WITH LIMITED INSTABILITY SUGGESTED BY THE NAM/RUC...THOUGH
IT IS CERTAINLY PLAUSIBLE THAT A CLAP OF THUNDER MAY APPROACH
NORTHWESTERN WISCONSIN. PRECIPITATION SHOULD DECREASE IN COVERAGE
THIS AFTERNOON AND MORE SO THIS EVENING.
FOG WILL BE COMMON TONIGHT INTO EARLY SATURDAY MORNING AS
PRECIPITATION DIMINISHES SIGNIFICANTLY...AND WINDS SLACKEN A
TOUCH.
DONOFRIO
PREV DISCUSSION... /ISSUED 309 AM CST FRI MAR 12 2010/
DISCUSSION...SHORT TERM REMAINS ON PCPN AND FOG. MAIN SFC LOW
CENTER CONTINUES TO FLOAT AROUND WEST CENTRAL IA WHILE ANOTHER
WEAK SFC REFLECTION IS ORGANIZING IN SOUTHERN WI. THE WI LOW IS IN
RESPONSE TO UPPER LEVEL ENERGY ROTATING WESTWARD FROM NE WI. THIS
SFC LOW WILL DRIFT INTO NW WI WHILE THE UPPER LEVEL ENERGY EVOLVES
INTO A CLOSED LOW IN THE SAME VICINITY. MORE RAIN WILL ACCOMPANY
THESE FEATURES TODAY AND HAVE ALIGNED POPS ACCORDINGLY. THE RAIN
WILL FURTHER THE SNOW MELT AND COMBINE WITH GENERALLY LIGHT WINDS
TO ALLOW THE FOG TO PERSIST. SOME AREA RIVERS ARE BEGINNING TO
OPEN UP AS A RESULT. SOME ICE JAMS MAY OCCUR ON RIVERS PRONE TO
ICE JAMS. RAINFALL AMOUNTS WILL BE LIGHT SO NO FLOODING ISSUES
EXPECTED ATTM. CANCELLED THE DENSE FOG ADVISORY AS CRITERIA IS NO
LONGER BEING MET AND WITH ANTICIPATED RAIN...VSBYS SHOULD REMAIN
GREATER THAN 1/4 MILE.
AS THE UPPER LOW SLOWLY MOVES TO THE WEST...WILL SEE A BREAK IN THE
ACCUMULATING RAIN TONIGHT. THE BULK OF THE LIFT WILL ACCOMPANY THE
UPPER LOW..BUT ENOUGH WILL LINGER TO SQUEEZE OUT SOME ISOLD
SHOWERS/DRIZZLE. MORE FOG EXPECTED AS SFC WIND WILL BE RELATIVELY
LIGHT.
THE CUT OFF LOW WILL MEANDER FURTHER WESTWARD INTO EASTERN ND ON
SATURDAY. MEANWHILE...ONE MORE SPOKE OF SHORT WAVE ENERGY WILL CLIP
THE EASTERN TIER OF THE FA IN THE MORNING. HAVE POPS IN PLACE TO
ACCOUNT FOR THIS WAVE. BY SATURDAY AFTERNOON...THE FA IS UNDER THE
INFLUENCE OF A COL AND EXPECT ACCUMULATING RAIN TO END. HAVE A
MENTION OF DRIZZLE AND MORE FOG AS UPPER LEVEL DIVERGENCE REMAINS IN
THE NEIGHBORHOOD FROM THE UPPER LOW. /GSF
EXTENDED...SATURDAY NIGHT THROUGH WEDNESDAY...
THE MAIN FORCING ASSOCIATED WITH THE DEPARTING UPPER LEVEL LOW WILL
BE WELL SOUTH OF OUR AREA AND EAST OF OUR AREA. FOG WILL STILL BE
AROUND ON SATURDAY NIGHT AND HAVE ADDED THIS TO THE FORECAST FOR
THIS PERIOD. A PIECE OF ENERGY FROM THIS UPPER LOW WILL BREAK OFF
FROM ITS PARENT SYSTEM...AND THIS WILL KEEP A SMALL CHANCE FOR A
RAIN SHOWER AROUND ON SUNDAY INTO MONDAY...WITH THE BEST CHANCES
FOCUSED IN OUR WESTERN AREAS.
ANOTHER DISTURBANCE WILL THEN SWING THROUGH THE AREA MONDAY INTO
TUESDAY...BUT THE CONSISTENT ECMWF HAS BEEN SLOWER THAN THE GFS WITH
THIS NEXT WAVE...AND HAS ALSO BEEN DRY FOR THE MOST PART...WHILE
WEAKENING THE UPPER DISTURBANCE WITH HIGH PRESSURE BUILDING IN. WITH
VERY WEAK LIFT EXPECTED AND NO TRUE SURFACE
REFLECTION...SIGNIFICANT MODEL DIFFERENCES IN TIMING... AND NOT
WANTING TO DO ANY FLIP-FLOPPING WITH POPS...WE WILL LEAVE THE
FORECAST DRY FOR MONDAY NIGHT INTO TUESDAY.
BY MIDWEEK...CONDITIONS SHOULD BE MAINLY DRY AND MILD AS A RIDGE OF
HIGH PRESSURE BUILDS IN FROM THE NORTHWEST. TEMPERATURES WILL
CONTINUE TO BE ABOVE NORMAL THROUGH THE WEEKEND...WITH THE
WARMEST TEMPS MOST LIKELY ON SUNDAY. A BRIEF COOL DOWN IS EXPECTED
TUESDAY...BUT WAA REALLY PICKS BACK UP ON WEDNESDAY. /DONOFRIO
&&
.POINT TEMPS/POPS...
DLH 39 35 39 34 / 70 30 20 20
INL 44 35 47 34 / 40 30 20 20
BRD 45 35 46 37 / 70 40 20 20
HYR 49 39 50 37 / 60 30 20 20
ASX 44 38 44 37 / 70 30 20 20
&&
.DLH WATCHES/WARNINGS/ADVISORIES...
MN...NONE.
WI...NONE.
&&
$$
EOM/CANNON/CANNON
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