Area Forecast Discussion
Issued by NWS Detroit/Pontiac, MI

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FXUS63 KDTX 260746
AFDDTX

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE DETROIT/PONTIAC MI
346 AM EDT SUN OCT 26 2014

.SHORT TERM...TODAY AND TONIGHT

DRY AIRMASS IN PLACE...AS SEEN IN 00Z DTX RAOB...AND WITH CU RULE
DECIDINGLY POSITIVE (EXCEPTION OVER FAR NORTHERN THUMB REGION) FOR
TODAY...LOOKING AT SUNNY FORECAST...WITH MAXES ABOUT 10 DEGREES
COOLER COMPARED TO YESTERDAY...UPPER 50S TO AROUND 60 DEGREES...PER
LATEST MAV GUIDANCE. WITH CONTINUED DRY AIRMASS IN PLACE TONIGHT AND
SURFACE HIGH/RIDGE ON TOP OF SOUTHEAST MICHIGAN...SHOULD BE
FAVORABLE RADIATING NIGHT...BUT SOME WARM ADVECTION HIGH CLOUDS LOOK
TO BE STREAMING IN LATE TONIGHT...WHICH SHOULD BE ENOUGH TO HOLD
MINS IN THE 30S.

&&

.LONG TERM...MONDAY THROUGH SATURDAY

A WARM FRONT LIFTING NORTH THROUGH THE CENTRAL GREAT LAKES ON MONDAY
WILL BRING WARMER TEMPERATURES AND THE CHANCE FOR RAIN TO PORTIONS
OF SOUTHEAST MICHIGAN. THE SURGE OF WARM AIR WILL BRING TEMPERATURES
ABOUT 10 DEGREES ABOVE NORMAL ON MONDAY AS 850 MB TEMPERATURES RISE
TO 12 TO 14 CELSIUS. RAIN CHANCES WILL MAINLY BE CONFINED TO THE
NORTHERN CWA CLOSE TO THE SURFACE WARM FRONT...WITH DRY WEATHER
EXPECTED ACROSS THE SOUTH DEEPER IN THE CAPPED WARM SECTOR.
THUNDERSTORMS WILL ALSO BE POSSIBLE GIVEN THE UNSTABLE CONDITIONS
AFFORDED BY THE WARM MOIST AIR. HIGHS WILL VARY GREATLY ON
MONDAY...WITH HIGHS AROUND 60 ACROSS THE THUMB GIVEN A SOUTHEASTERLY
SURFACE WIND OFF LAKE HURON AND HIGHS AROUND 70 NEAR THE OHIO
BORDER AWAY FROM THE MAIN PRECIPITATION AND DEEPER INTO THE WARM
SECTOR.

THE MAIN LOW WILL BECOME ORGANIZED OVER THE WESTERN GREAT LAKES
MONDAY NIGHT AS A DEEP MID LEVEL TROUGH OUT TO THE WEST BECOMES
NEGATIVELY TILTED AND A STRONG 110 KNOT 250 MB UPPER LEVEL JET MAKES
ITS WAY OVER THE MID MISSISSIPPI VALLEY. THE LOW ITSELF WILL THEN
TRACK NORTHEAST TOWARDS JAMES BAY ON TUESDAY...PUSHING A STRONG COLD
FRONT THROUGH THE CENTRAL GREAT LAKES ON TUESDAY. THE MODELS HAVE
COME INTO EVEN BETTER AGREEMENT THIS RUN WITH THE LOW AND ASSOCIATED
COLD FRONT...CLEARING THE CWA BY EARLY AFTERNOON...WITH DRY COOL AIR
QUICKLY ENDING SHOWERS DURING THE AFTERNOON HOURS FROM WEST TO EAST.
WITH THE BETTER MODEL AGREEMENT FEEL CONFIDENT ENOUGH TO LOWER POPS
SIGNIFICANTLY AFTER 18Z TUESDAY INTO THE LOW CHANCY CATEGORY.
CONTINUED INSTABILITY WILL KEEP THUNDERSTORMS IN THE FORECAST DURING
THIS TIME PERIOD UNTIL THE COLD FRONT CLEARS THE AREA.

A PUSH OF COLD DRY AIR BEHIND THE COLD FRONT WILL PUSH DAYTIME HIGHS
BACK DOWN TO REALITY ON WEDNESDAY WITH AFTERNOON HIGHS LIMITED TO
THE LOWER 50S AS WEAK RIDGING KEEPS THE WEATHER DRY BUT WITH
CONTINUED CLOUD COVER GIVEN THE CONTINUED MID LEVEL CYCLONIC FLOW.

ANOTHER LOW PRESSURE SYSTEM WILL BRING ADDITIONAL CHANCES FOR RAIN
LATE IN THE WEEK AS WELL AS A REINFORCING SHOT OF COLD AIR LATE TO
THE CENTRAL GREAT LAKES. TEMPERATURES WILL TAKE A STEADY FALL FROM
AROUND 50 ON THURSDAY...TO AROUND 40 BY SATURDAY AFTERNOON. ALTHOUGH
THIS LOW WILL NOT PACK MUCH OF A PUNCH PRECIPITATION WISE...IT WILL
BRING THE COLDEST AIR OF THE SEASON AS 850 MB TEMPERATURES FALL TO
AROUND -10 CELSIUS BY SATURDAY AFTERNOON. WITH THE COLD AIR AND
NORTHERLY TRAJECTORY THERE IS A CHANCE FOR SOME SNOW TO MIX IN WITH
THE LAKE EFFECT SHOWERS ACROSS THE EASTERN THUMB FRIDAY NIGHT.

&&

.MARINE...

.A STRONG LOW NEAR JAMES BAY WILL CAUSE GUSTY NORTHWEST WINDS EARLY
THIS MORNING. THE STRONGEST WINDS WILL BE OVER THE NORTHERN HALF OF
LAKE HURON WHERE A COLDER AIRMASS WILL SUPPORT WINDS GUSTING TO LOW-
END GALES. IN ADDITION...SMALL CRAFT ADVISORIES ARE IN EFFECT FOR
THE EXPOSED NEARSHORE WATERS OF THE THUMB WHERE SIGNIFICANT WAVES
HEIGHTS ARE EXPECTED TO BUILD TO SEVERAL FEET. WINDS AND WAVES WILL
SUBSIDE THIS AFTERNOON...WITH RELATIVELY TRANQUIL CONDITIONS
EXPECTED ACROSS THE CENTRAL GREAT LAKES TONIGHT.

&&

.AVIATION...ISSUED 1148 PM EDT SAT OCT 25 2014

//DISCUSSION...

NIGHTTIME COOLING AND A GRADUAL WEAKENING OF THE SURFACE GRADIENT
WILL SUPPORT WIND SPEEDS DROPPING AND/OR REMAINING BELOW 10 KNOTS
THROUGH DAYBREAK. A VERY DRY POST FRONTAL AIRMASS WILL MAINTAIN
CLEAR SKIES THROUGH MOST OF THE TAF PERIOD.

//DTW THRESHOLD THREATS...

* NONE.

&&

.DTX WATCHES/WARNINGS/ADVISORIES...
MI...NONE.

LAKE HURON...
     SMALL CRAFT ADVISORY...OUTER SAGINAW BAY AND THE NEARSHORE WATERS
     FROM PORT AUSTIN TO PORT SANILAC...UNTIL 4 PM SUNDAY.

LAKE ST CLAIR...NONE.
MI WATERS OF LAKE ERIE...NONE.

&&

$$

SHORT TERM...SF
LONG TERM....KURIMSKI
MARINE.......KURIMSKI
AVIATION.....SC


YOU CAN OBTAIN YOUR LATEST NATIONAL WEATHER SERVICE FORECASTS ONLINE
AT WWW.WEATHER.GOV/DETROIT (ALL LOWER CASE).



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