Area Forecast Discussion
Issued by NWS Detroit/Pontiac, MI

Home | Current Version | Previous Version | Text Only | Print | Product List | Glossary Off
Versions: 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50

000
FXUS63 KDTX 220650
AFDDTX

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE DETROIT/PONTIAC MI
250 AM EDT MON SEP 22 2014

.SHORT TERM...TODAY AND TONIGHT

AN UPPER LEVEL TROUGH AND ASSOCIATED SHORTWAVE...CLEARLY VISIBLE ON
SATELLITE IMAGERY...ARE CURRENTLY MAKING THEIR WAY THROUGH THE
CENTRAL GREAT LAKES EARLY THIS MORNING. RIDGING WILL BUILD IN BEHIND
THE TROUGH THROUGHOUT THE DAYTIME HOURS AS DRIER AIR ADVECTS IN FROM
THE WEST AS SURFACE WINDS BACK TO THE WEST THIS AFTERNOON...AND
EVENTUALLY SOUTHWEST DURING THE OVERNIGHT HOURS. AS THE 00Z KDTX
RAOB SOUNDING INDICATES THERE IS QUITE A BIT OF MOISTURE TRAPPED IN
THE LOW LEVELS...AS EVIDENCED BY THE STRATUS DECK CURRENTLY IN
PLACE. MODEL SOUNDINGS AND UPSTREAM OBSERVATIONS INDICATE THESE
CLOUDS WILL DISSIPATE AS THE HIGH TRACKS EAST AS EVIDENCED BY THE
VERY DRY AIR LOCATED OVER THE WESTERN GREAT LAKES ASSOCIATED WITH
THE HIGH.

DESPITE CLEARING SKIES DURING THE AFTERNOON HOURS...SUNSHINE WILL
NOT BE ENOUGH TO MAKE UP FOR THE VERY COLD AIRMASS AND SHALLOW
MIXING DEPTHS IN PLACE ACROSS THE AREA. THESE CONDITIONS LOOK TO
LIMIT HIGH TEMPERATURES TO AROUND 60 DEGREES THIS AFTERNOON.
ALTHOUGH CLEAR SKIES AND LIGHT WINDS WILL PROVIDE IDEAL RADIATING
CONDITIONS TONIGHT WITH THE HIGH JUST TO OUR SOUTH...THE AREA WILL
ALREADY BE RECOVERING FROM THE SHOT OF COLD AIR AS 850 MB
TEMPERATURES IMPROVE TO AROUND 10 DEGREES DURING THE OVERNIGHT
HOURS. STILL...LOW TEMPERATURES LOOK TO BOTTOM OUT IN THE MIDDLE 40S
ACROSS MUCH OF THE AREA.

&&

.LONG TERM...

A PROLONGED PERIOD OF UPPER RIDGING IS POISED TO TAKE HOLD OF THE
GREAT LAKES REGION RESULTING IN AN EXTENDED PERIOD OF MOSTLY SUNNY
SKIES...TEMPERATURES IN THE 70S...AND DRY WEATHER. THE COOLEST DAY OF
THE LONG TERM PERIOD WILL BE THE FIRST. TUESDAY WILL BE
CHARACTERIZED BY A REBOUNDING THERMAL FIELD AS TODAY`S THERMAL
TROUGH EXITS EAST. UPPER RIDGING WILL BUILD IN THROUGH THE DAY,
BEING NUDGED EAST BY THE EASTWARD PROGRESSION OF THE GREAT BASIN
CLOSED LOW. H85 TEMPS WILL EVENTUALLY APPROACH 12C BY 00Z WED, BUT
IT WILL BE TOO LITTLE TOO LATE AS FAR AS MIXING GOES. AS A RESULT,
HIGHS WILL BARELY TOUCH 70 IN MOST SPOTS.

THE REMAINDER OF THE LONG TERM WILL BE BAROTROPIC IN CHARACTER BUT
STRONGLY CAPPED. A PIECE OF THE CLOSED LOW WILL SHEAR EAST AS IT IS
ABSORBED BACK INTO THE PREVAILING WESTERLIES ON WEDNESDAY AFTERNOON.
THIS WILL OCCUR OVER THE WESTERN GREAT LAKES AND WILL BE OF NO
CONSEQUENCE LOCALLY OTHER THAN A FEW MID/HIGH CLOUDS THURSDAY. THE
REMAINDER OF THAT LOW WILL CUT BACK TO THE WEST...BEST ILLUSTRATED BY
THE 0.6 PVU SURFACE AT 500MB...AS IT WORKS IN CONCERT WITH THE
DEEPENING WEST COAST TROUGH TO FORCE A WAVE BREAK OVER THE CONUS.
THE RESULTANT CUTOFF RIDGE WILL SETTLE OVER THE GREAT LAKES FOR THE
WEEKEND...ENSURING CONTINUED CAPPING. THIS RIDGE WILL CARRY WITH IT
LITTLE IN THE WAY WAY OF WARMER AIR IN THE LOW-LEVELS DESPITE
PROGGED H5 HEIGHTS UP TO 592DM OVER MICHIGAN. AS A RESULT...ONLY
MINOR TEMPERATURE MODIFICATION INTO THE UPPER 70S...PERHAPS TOUCHING
80 ON A COUPLE OF OVERACHIEVING DAYS, IS EXPECTED. WITH CLEAR SKIES
AND A LIGHT GRADIENT...MORNING LOWS SHOULD STILL HOVER NEAR NORMAL
VALUES IN THE LOW/MID 50S EACH MORNING. A COUPLE MORNINGS FEATURING
RADIATION FOG WILL ALSO BE POSSIBLE.

&&

.MARINE...

GUSTY NORTHWEST WINDS WILL BACK TO THE WEST AND EASE THROUGH THE
DAY. SUBSIDING WAVE HEIGHTS WILL SOON TO FOLLOW WHICH WILL FINALLY
ALLOW THE POSTED SMALL CRAFT ADVISORIES FOR THE NEARSHORE WATERS OF
LAKE HURON TO EXPIRE LATER TODAY. THE REMAINDER OF THE FORECAST
PERIOD WILL FEATURE LIGHT TO OCCASIONALLY MODERATE WINDS WITH NO
PRECIPITATION.

&&

.AVIATION...ISSUED 1153 PM EDT SUN SEP 21 2014

//DISCUSSION...

A DEEP LOW LEVEL INVERSION /SHOWN IN THE 00Z APX SOUNDING/ WILL
MAINTAIN STRATUS ACROSS SE MI THROUGH DAYBREAK. THE CEILINGS LOOK
TO HOVER AROUND THE 3000 FT THRESHOLD MUCH OF THE NIGHT. ONGOING
LOW LEVEL DRY AIR ADVECTION MAY ACTUALLY LIFT BASES JUST A BIT BY
DAYBREAK. A CLEARING TREND IS EXPECTED BY EARLY MON AFTERNOON AS
THE DRY AIR MIXES INTO THE CLOUD LAYER.

//DTW THRESHOLD THREATS...

* HIGH CONFIDENCE IN CIGS BELOW 5KFT TONIGHT...MEDIUM CONFIDENCE
MONDAY MORNING.

&&

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

LAKE HURON...
     SMALL CRAFT ADVISORY...OUTER SAGINAW BAY AND THE NEARSHORE WATERS
     FROM PORT AUSTIN TO HARBOR BEACH...UNTIL 10 AM MONDAY.

     SMALL CRAFT ADVISORY...INNER SAGINAW BAY...UNTIL 8 AM MONDAY.

     SMALL CRAFT ADVISORY...NEARSHORE WATERS FROM HARBOR BEACH TO PORT
     HURON...UNTIL 4 PM MONDAY.

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

&&

$$

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


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





USA.gov is the U.S. government's official web portal to all federal, state and local government web resources and services.