970 FXUS63 KDTX 060657 AFDDTX AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE DETROIT/PONTIAC MI 257 AM EDT MON MAY 6 2013 .SHORT TERM...TODAY AND TONIGHT AREA REMAINS UNDER THE SAME WEATHER PATTERN AS UPPER LOW DRIFTS SLOWLY EAST ACROSS THE DEEP SOUTH. FEED OF MOISTURE HAS SLOWLY INCREASED TO THE NORTH/NORTHEAST OF THIS SYSTEM AND WILL FEED ADDITIONAL CLOUDINESS INTO THE OHIO VALLEY AND PARTS OF SOUTHERN MICHIGAN...WITH A FEW SHOWERS NOT ALL THAT FAR FROM THE MICHIGAN AND OHIO STATELINE. WILL MAINTAIN THE DRY FORECAST FOR THE ENTIRE AREA BUT EXPECT SLIGHTLY MORE CLOUDINESS OVER THE SOUTHERN CWA AS CIRRUS WILL BE A BIT THICKER TODAY GIVEN THIS FEED OF MOISTURE AROUND THE UPPER LOW. BETWEEN THE ADDITIONAL CLOUDINESS OVER THE SOUTHERN CWA...AND THE CONTINUED EAST FLOW OFF OF THE GREAT LAKES...TEMPERATURES WILL ONCE AGAIN RANGE IN THE UPPER 60S TO AROUND 70 FAR FROM DETROIT SOUTH TO THE MIDDLE 70S OVER THE SAGINAW VALLEY WHERE BOTH OF THESE "COOLING" INFLUENCES WILL BE ESSENTIALLY NON-EXISTENT. THERE WILL BE A SLIGHT CHANGE IN THE LOW LEVELS LATE TONIGHT AS A RIDGE OF HIGH PRESSURE...WHICH HAS BEEN POISED JUST TO THE NORTH FOR DAYS...WILL BUILD INTO AT LEAST THE NORTHERN CWA. THIS WILL PROVIDE BETTER RADIATIONAL COOLING AS WINDS BECOME CALM IN SOME LOCATIONS. SO...40S WILL BE MORE WIDESPREAD...WITH INLAND THUMB LOCATIONS EVEN APPROACHING 40. ANY LOW TEMPERATURES IN THE LOWER 50S WILL BE LIMITED TO AREAS FROM METRO DETROIT SOUTH...WITH A GENERAL RANGE OF 48-52 EXPECTED FOR THE MORE SOUTHERN LOCATIONS. && .LONG TERM...TUESDAY THROUGH SUNDAY EVOLUTION OF THE PATTERN OF WAVE BREAKING ACROSS THE EASTERN UNITED STATES WILL COME TO COMPLETION OVER THE NEXT FEW DAYS AS THE LARGE CLOSED CIRCULATION TO OUR SOUTH LIFTS NORTHWARD ALONG THE EASTERN SEABOARD AND IS REABSORBED INTO PREVAILING WESTERLIES BY LATE THURSDAY. WITH NO EXCHANGE OF AIRMASS OCCURRING DURING THIS TIME, TEMPERATURES WILL REMAIN ESSENTIALLY UNCHANGED WITH ONLY MINOR DAILY ADJUSTMENTS REFLECTING PRESSURE GRADIENT AND CLOUD EXPECTATIONS. MID-LEVEL MOISTURE WILL GRADUALLY INCREASE THROUGH THE WEEK FIRST AS A RESULT OF INCREASING PROXIMITY TO THE CLOSED LOW AS IT LIFTS NORTH AND LATER WITH THE APPROACH OF THE LOW AMPLITUDE WAVE CURRENTLY SEEN OVER THE NORTHERN PLAINS. CLOUD COVERAGE WILL BE STRONGLY TIED TO THE DIURNAL HEATING CYCLE AND WILL PROGRESSIVELY INCREASE EACH DAY. IN ADDITION, IMPROVING MOISTURE QUALITY AND APPROACH OF MODEST MID-LEVEL FORCING FROM THE WEST WILL SPELL INCREASING CHANCES FOR SHOWERS TUES-THURS WITH THE HIGHEST LIKELIHOOD ON ANY GIVEN DAY INVOF THE INLAND THERMAL TROUGH. POTENT HIGH-LATITUDE ENERGY WILL THEN DRIVE AN AMPLIFICATION OF THE LONGWAVE PATTERN THAT WILL USHER IN COOLER TEMPERATURES BY THE END OF THE FORECAST PERIOD. && .MARINE... A CONTINUED STAGNANT WEATHER PATTERN CHARACTERIZED BY A WEAK SURFACE PRESSURE GRADIENT WILL MAINTAIN GENTLE TO MODERATE EAST TO SOUTHEAST WINDS ACROSS AREA WATERS DURING THE UPCOMING WEEK. SIGNIFICANT WAVE HEIGHTS WILL REMAIN AT 2 FEET OR LESS. THIS PATTERN BEGINS TO BREAK DOWN BY FRIDAY...AS A BACKDOOR COLD FRONT LEADS TO SLIGHTLY STRONGER NORTHEAST ONSHORE FLOW AND HIGHER WAVES...BUT ANY SIGNIFICANT CHANGE HOLD OFF UNTIL A STRONG COLD FRONT MOVES THROUGH THE REGION THIS WEEKEND. && .AVIATION...ISSUED 1155 PM EDT SUN MAY 5 2013 //DISCUSSION... SOUTHEAST MICHIGAN WILL REMAIN WITHIN A DRY AND STABLE ENVIRONMENT NORTH OF A SLOW MOVING LOW PRESSURE SYSTEM THROUGH MONDAY. PATCHES OF THICKER MID AND HIGH LEVEL CLOUD COVER WILL DRIFT THROUGH AT TIMES. WIND WILL REMAIN OUT OF THE EAST HOLDING GENERALLY AT 10 KNOTS OR LESS. //DTW THRESHOLD THREATS... * NONE && .DTX WATCHES/WARNINGS/ADVISORIES... MI...NONE. LAKE HURON...NONE. LAKE ST CLAIR...NONE. MI WATERS OF LAKE ERIE...NONE. && $$ SHORT TERM...DG LONG TERM....JVC MARINE.......DG AVIATION.....MR YOU CAN OBTAIN YOUR LATEST NATIONAL WEATHER SERVICE FORECASTS ONLINE AT WWW.WEATHER.GOV/DETROIT (ALL LOWER CASE).