000
FXUS63 KMPX 221016
AFDMPX

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE TWIN CITIES/CHANHASSEN MN
516 AM CDT WED MAY 22 2013

.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 410 AM CDT WED MAY 22 2013

COOL AND CLOUDY WITH LIGHT RAIN SHOWERS WILL BE THE STORY TODAY.
MOST OF THE FORECAST AREA IS IN THE UPPER 40S TO LOWER 50S WITH DAMP
CONDITIONS AND A NORTHEASTERLY BREEZE EARLY THIS MORNING...SO IT IS
DEFINITELY JACKET WEATHER OUT THERE. WE COOLED TEMPERATURES TODAY BY
A COUPLE DEGREES FROM THE PREVIOUS FORECAST IN ORDER TO KEEP MOST OF
THE AREA IN THE 50S FOR HIGHS...THE EXCEPTION WOULD BE PORTIONS OF
WEST CENTRAL WI WHICH SHOULD BE A FEW DEGREES WARMER. THERE IS VERY
LITTLE TEMPERATURE ADVECTION TODAY AND WITH THE LINGERING CLOUDS AND
LIGHT RAIN IN THE FORECAST...WE MIGHT ONLY BE ABLE TO WARM 6-8
DEGREES FROM WHERE TEMPERATURES STAND NOW. YESTERDAY...ST.CLOUD ONLY
HIT 50 DEGREES FOR A HIGH GIVEN THE COOLING FROM THE NEARLY 0.50" OF
RAIN THAT FELL. THE RAIN WON`T BE NEARLY AS HEAVY TODAY...BUT THE
TEMPS WILL STILL SUFFER AND THERE MAY ACTUALLY BE SLIGHTLY BETTER
LIGHT RAIN/SHOWER COVERAGE TODAY. THERE IS A BACK EDGE TO THE CLOUD
COVER IN NORTHERN MINNESOTA WHICH MEANS THERE WILL BE NICE DIURNAL
WARMING ACROSS THE NORTHERN HALF OF THE STATE BY THIS AFTERNOON. IF
THE CLOUD CLEAR BEFORE OR AROUND THE NOON HOUR IN CENTRAL MN...THE
WE WILL LIKELY BE TOO LOW WITH TEMPS ACROSS NORTHERN PORTIONS OF THE
FORECAST AREA. HOWEVER...THE CLEARING TREND DOES MEAN WE HAVE HIGH
CONFIDENCE IN THE RAIN MOVING OUT TONIGHT. THE DEWPOINT DEPRESSIONS
/OUTSIDE OF THE LOWER BOUNDARY LAYER/ OFF THE MODEL FORECAST
SOUNDINGS SHOW NICE DRYING AFTER MIDNIGHT.

THE ONLY OTHER FORECAST CONCERN IS FOR THE POTENTIAL FOR A LITTLE
FOG EARLY THIS EVENING IMMEDIATELY AFTER THE CLOUDS CLEAR. IT IS NOT
A BIG CONCERN THROUGH BECAUSE WE ARE QUICKLY ADVECTING IN DRIER AIR
FROM THE NORTHEAST AS WE HEAD TOWARD THURSDAY MORNING. WE LEFT THE
FOG OUT FOR NOW. WE ALSO KEPT THE THUNDER OUT OF THE FORECAST TODAY
EVEN THOUGH ISOLATED THUNDER IS STILL POSSIBLE ACROSS IA/WI AND
SOUTHEAST MN. WE JUST DON`T HAVE THE INSTABILITY TO BE CONCERNED TOO
MUCH WITH THIS. IN FACT...WE EVEN ENTERTAINED THE IDEA OF CHANGING
THE WEATHER FROM LIGHT RAIN SHOWERS TO SPRINKLES/DRIZZLE TODAY. IT
ALL AMOUNTS TO THE SAME THING...COOL AND DAMP.

.LONG TERM...(THURSDAY THROUGH TUESDAY)
ISSUED AT 410 AM CDT WED MAY 22 2013

THE PERIOD BEGINS WITH OUR PESKY LOW PRESSURE SYSTEM FINALLY TO
OUR SOUTHEAST ALONG WITH A SUBSTANTIAL CANADIAN HIGH PRESSURE
SYSTEM BUILDING SOUTH ACROSS THE UPPER MISSISSIPPI VALLEY REGION.
THURSDAY AND MUCH OF FRIDAY WILL BE FINE WEATHER DAYS FOR THE FA.
THE MAIN CONCERNS DURING THIS PERIOD CENTER AROUND VERY LOW
DEW POINTS THURSDAY AFTERNOON LEADING TO MIN RH VALUES NEAR 20
PERCENT IN OUR WI CWA AS WELL AS THE THREAT FOR SOME FROST/FREEZE
CONDITIONS...AGAIN MAINLY IN OUR WI COUNTIES THURSDAY NIGHT/FRIDAY
MORNING. USED THE MIX DOWN TD TOOL AS A START FOR THURSDAY
AFTERNOON ALONG WITH SOME CONSRAW/CONSMOS. THIS BROUGHT DEW POINTS
WELL DOWN INTO THE 20S OVER THE AFOREMENTIONED AREA. THE HIGH
PRESSURE SYSTEM WILL BE NEARLY OVERHEAD THURSDAY NIGHT. WITH LIGHT
WINDS...A CLEAR SKY AND DRY AIR IN PLACE...LOWS NEAR FREEZING
INDICATED AROUND LADYSMITH WITH MIDDLE 30S AS FAR WEST AS THE
MN/WI BORDER AND WELL AS TO THE NORTH OF THE TWIN CITIES.
INDICATED FROST IN VARYING DEGREES OF COVERAGE STARTING WITH LOWS
36 DEGREES OR COLDER.

BEGINNING WITH FRIDAY IS WHERE THINGS START TO SLOWLY UNWIND WITH
MODEL CONSISTENCY. THE NAM AT THIS POINT IS THE FASTEST ON FRIDAY
ON BRINGING BACK SHOWERS AND SOME THUNDERSTORMS ACROSS MUCH OF THE
MN CWA ON FRIDAY AS MOISTURE AND INSTABILITY BEGIN TO INCREASE ON
THE BACKSIDE OF THE HIGH. THE GEM/GFS AND EURO WOULD KEEP ALL BUT
THE FAR WEST DRY. THEREFORE...REMOVED THE MENTION OF POPS IN THE
12Z-18Z TIME FRAME AND KEPT THE 18Z-24Z POPS CONFINED TO THE FAR
WEST. THE GEM/GFS/EURO THEN INDICATED SCATTERED SHOWERS AND
THUNDERSTORMS ACROSS MUCH OF THE FA FRIDAY NIGHT AND SATURDAY.
PROBABILITIES FOR MEASURABLE PRECIPITATION ARE LEAST IN THE FAR
EASTERN WI COUNTIES. NOTHING TOO SIGNIFICANT (RAINFALL/SEVERE
WEATHER) EXPECTED AT THIS TIME AS SMALL RIPPLES IN THE UPPER FLOW
MIGRATE NORTHEAST OUT OF A LARGE UPPER TROUGH IN THE WESTERN
UNITED STATES.

PROGRESSING DEEPER INTO THE HOLIDAY WEEKEND SHOWS TWO CAMPS
THROUGH MEMORIAL DAY. THE GFS IS WET ACROSS US SUNDAY AND MONDAY
WHILE THE EURO IS BASICALLY DRY. THE DIFFERENCE IS SEEN IN THE
UPPER PATTERN. THE PESKY UPPER LOW THAT HAS TORMENTED US FOR THE
PAST FIVE DAYS REACHES THE EASTERN SEABOARD BY FRIDAY AND DEEPENS
AS MORE ENERGY DROPS INTO IT FROM THE NORTH. THE EURO IS DEEPEST
AND SLOWEST WITH THIS FEATURE WHICH ACTUALLY BUILDS THE SURFACE
HIGH BACK WEST FOR A TIME LATE IN THE WEEKEND. THE GEM DOES NOT
HAVE AN UPPER LOW AND ALLOWS FOR MORE PROGRESSION OF THE UPPER
PATTERN AND PLENTY OF RAINFALL. HENCE...CHANCES POPS INDICATES FOR
MANY PERIODS OF THE EXTENDED FORECAST DUE TO THE BLENDED GUIDANCE.

THE CIPS ANALOGS WERE LOOKED AT OVERNIGHT TO SEE WHAT SORT OF SEVERE
WEATHER OCCURRED WITH OUR PATTERN AHEAD. USING THE 144 HOUR
ANALOG GUIDANCE SHOWED ALL FORMS OF SEVERE WEATHER WITH THE MOST
CLUSTERING OVER SD/NE/KS/IA WITH SOME SEVERE WEATHER REPORTS OVER
FAR WESTERN AND FAR SOUTHERN MN. THIS CORRELATES WELL WITH THE GFS
HAVING LOW PRESSURE FORMING DURING THIS PERIOD OVER THE CENTRAL
PLAINS WITH A WARM FRONT MEANDERING TO THE LOWER OHIO VALLEY. THE
EURO WOULD BE A LITTLE SLOWER. SO WE MAY DODGE SEVERE WEATHER
DURING THE WEEKEND...BUT THE THREAT WILL BE ON THE INCREASE BY THE
MIDDLE OF NEXT WEEK AS THE LOW PRESSURE SYSTEM AND WARM FRONT
ADVANCE INTO THE NORTHERN PLAINS AND UPPER MISSISSIPPI VALLEY
REGION.

HIGH/LOW TEMPERATURES WILL BE MAINLY BELOW NORMAL THROUGH THE
WEEKEND WITH A CLIMB BACK ABOVE FOR EARLY NEXT WEEK.

&&

.AVIATION...(FOR THE 12Z TAFS THROUGH 12Z THURSDAY MORNING)
ISSUED AT 459 AM CDT WED MAY 22 2013

IFR CEILINGS WITH VFR/MVFR VISIBILITY EXPECTED THROUGH THE
MORNING WITH SCATTERED SHOWERS AND AREAS OF DRIZZLE. NOT TOO MUCH
TO ADD HERE BEYOND THE TAF. THE SHOWERS ARE HIT AND MISS...SO THE
VIS WILL BE DIFFICULT TO PREDICT WITH MUCH PRECISION. THE CEILINGS
WILL HANG BETWEEN 500-1200 FT THIS MORNING AND THEN SLOWLY IMPROVE
FROM NW-SE LATE THIS AFTERNOON. SKC IN MANY SPOTS BY THE LATE
EVENING. THREW IN A FEW HOUR TEMPO FOR FOG AT A COUPLE SITES AFTER
SKIES CLEAR AND BEFORE DRIER AIR MAKES IT IN.

KMSP...

LIFR OR IFR LOOKS TO LINGER THREW MOST OF THE MORNING WITH THE
CEILINGS BEING THE BIGGEST PROBLEM. EVENTUALLY THE AIRPORT SHOULD
GET ABOVE 1000 FT TODAY...BUT MVFR CEILINGS BELOW 1700 FT SHOULD
LINGER WELL INTO THE AFTERNOON AND COULD IMPACT THE EVENING RUSH.
THE LIGHT RAIN SHOWERS AND PATCHY DRIZZLE WILL BE IMPOSSIBLE TO
TIME IN AND OUT OF THE AIRPORT. RAIN MIGHT ACTUALLY BE A BIT
HEAVIER THIS AFTERNOON...BUT VIS SHOULD REMAIN NEAR OR ABOVE 4SM.

/OUTLOOK FOR KMSP/

THURSDAY...VFR CONDITIONS EXPECTED. NORTHEAST WIND 5 TO 15 KT.
THURSDAY NIGHT...VFR CONDITIONS EXPECTED. EAST WIND LESS THAN 10
KT BECOMING SOUTHEAST.
FRIDAY...VFR CONDITIONS EXPECTED. SOUTHEAST WIND 5 TO 15 KT.
SATURDAY...MVFR CEILINGS AND VISIBILITIES POSSIBLE WITH A CHANCE
OF SHOWERS AND THUNDERSTORMS. SOUTHEAST WIND 10 TO 20 KT.

&&

.MPX WATCHES/WARNINGS/ADVISORIES...
MN...NONE.
WI...NONE.
&&

$$

SHORT TERM...CLF
LONG TERM...RAH
AVIATION...CLF