Area Forecast Discussion
Issued by NWS Detroit/Pontiac, MI

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
-- Highlight Changed Discussion --
-- Discussion containing changed information from previous version are highlighted. --
000 FXUS63 KDTX 030806 AFDDTX AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE DETROIT/PONTIAC MI 406 AM EDT MON AUG 3 2015 .SHORT TERM...TODAY AND TONIGHT DEEP CYCLONIC FLOW IS OVERSPREADING SOUTHEASTERN MICHIGAN THIS MORNING AS A CLOSED LOW HEIGHT ANOMALY QUICKLY AMPLIFIES OVER MUCH OF EASTERN CANADA. NWP AND SATELLITE IMAGERY SUPPORTS A LACK OF ANY SIGNIFICANT SHORTWAVE ENERGY OR CYCLONIC VORTICITY ADVECTION FOR TODAY UNDERPINNING WHAT WILL BE A LACK OF SYNOPTIC SCALE FORCING FOR ASCENT. RATHER OVERALL DYNAMICS APPEAR TO BE GOVERNED BY ISENTROPIC DOWNGLIDE. AN EXCEPTION FOR A COMPLETELY DRY FORECAST WILL BE OVER PORTIONS OF NORTHERN LOWER...NORTHERN LAKE HURON...AND DOWN INTO THE NORTHERN THUMB WHERE A LOW CHANCE OF A SHOWERS WILL EXIST. A STEEP LAPSE RATE 800-700MB LAYER IS FORECASTED TO STREAM INTO THESE AREAS DURING THE LATE AFTERNOON AND EVENING HOURS. MODEST DEFORMATION AND FGEN FORCING WILL BE POSSIBLE AHEAD OF LOW TO MIDLEVEL TEMPERATURE GRADIENT WITH THE SHALLOW NATURE OF THE HIGH BASED INSTABILITY LIMITING THE OVERALL POTENTIAL. DAYTIME TEMPERATURES WILL RANGE IN THE UPPER 70S OVER MUCH OF THE AREA WITH SOME SNEAKY LOW TO POSSIBLY MID 80 DEGREE READINGS FOR THE HIGHER SURFACE PRESSURE AREAS/HEAT ISLAND SOUTH AND EAST OF THE TERRAIN. && .LONG TERM... VERY LARGE UPPER LEVEL LOW/CIRCULATION ENCOMPASSING CENTRAL/EASTERN CANADA EARLY THIS WEEK. SEVERAL UPPER LEVEL DISTURBANCES PINWHEELING AROUND THE CIRCULATION. ONE SUCH UPPER WAVE DESCENDING FROM WESTERN HUDSON BAY EARLY THIS MORNING IS EXPECTED TO SWING THROUGH THE NORTHERN GREAT LAKES ON TUESDAY...TIGHTENING UP THE 500 MB TEMPERATURE GRADIENT ACROSS THE CENTRAL GREAT LAKES. HOWEVER...WITH DRIER LOW LEVEL AIR (SURFACE DEW PTS IN THE 50S) IN PLACE...LI`S LOOK TO REMAIN POSITIVE. HOWEVER...GOOD 850-700 MB LAPSE RATES SHOULD SUPPORT A SUBSTANTIAL CU UP DURING THE DAY WITH CAPES AROUND 100 J/KG ...AND WILL MAINTAIN LOW CHANCE POPS ACROSS THE NORTH FOR LIGHT SHOWERS...ESPECIALLY ACROSS THE NORTHERN THUMB REGION...WHERE ADDED MOISTURE BOOST FROM SAGINAW BAY MAY COME INTO PLAY. 850 MB TEMPS RANGING FROM UPPER SINGLE NUMBERS NORTH TO LOWER TEENS NEAR THE OHIO BORDER...TRANSLATING TO HIGHS IN THE MID 70S TO AROUND 80 DEGREES. CONTINUED MODEST COOLING WEDNESDAY AND THURSDAY AS HIGH PRESSURE BUILDING OVER LOWER MICHIGAN PROMOTES LESS DAYTIME MIXING...RESULTING IN HIGHS IN THE 70S. FAVORABLE RADIATING NIGHTS TRANSLATING TO MINS IN THE 50S. WILL HAVE TO WATCH UPPER WAVE COMING OUT OF THE FOUR CORNERS REGION...AS 00Z EURO TRACKS THE 500 MB TROUGH THROUGH THE OHIO VALLEY DURING THURSDAY...AND IT IS POSSIBLE A FEW SHOWERS COULD SNEAK TO THE SOUTHERN MICHIGAN BORDER OR JUST NORTH....DEPENDING ON STRENGTH AND EXACT LOCATION OF THIS MID LEVEL CIRCULATION. && .MARINE... COLD FRONT HAS CLEARED THE CENTRAL GREAT LAKES THIS MORNING...AND LOOKING AT WEST TO NORTHWEST WINDS OF 10 TO 20 KNOTS THROUGH THE DAY. ALL SMALL CRAFTS ADVISORIES HAVE BEEN ALLOWED TO EXPIRE. A SECONDARY FRONT AND COOLER AIR ARRIVING FOR TUESDAY WILL INCREASE WINDS OVER NORTHERN LAKE HURON INTO THE 20 TO 25 KNOT RANGE HOWEVER...SLOWLY DECREASING AS WE HEAD INTO WEDNESDAY. HIGH PRESSURE IN CONTROL FOR THURSDAY WILL THEN PROVIDE AND LIGHT AND VARIABLE WIND FIELD. && .AVIATION...ISSUED 125 AM EDT MON AUG 3 2015 LINE OF THUNDERSTORMS HAS SETTLED INTO PORTIONS OF OHIO AND INDIANA. TRAILING STRATIFORM PRECIPITATION WITH EMBEDDED LIGHTNING WILL IMPACT THE SOUTHERN TERMINALS INTERMITTENTLY DURING THE FIRST HOUR OR TWO OF THE TAF CYCLE. RESIDUAL MOISTURE WITH ONSET OF LOW LEVEL COLD AIR ADVECTION SHOULD ALLOW IFR STRATUS DECK TO FILL IN ACROSS THE NORTHERN HALF OF THE AREA. OBSERVING PLATFORMS HAVE RECORDED THE IFR CIGS NOW ITS A QUESTION OF OVERALL DEVELOPING COVERAGE. KEPT CIGS AT BORDERLINE IFR/MVFR FOR THE DETROIT TERMINALS. DEVELOPING BOUNDARY LAYER TODAY WILL LEAD TO WEST WINDS OF 10 TO 20 KNOTS. LOSS OF DAYTIME HEATING AND DRY AIR ADVECTION IS EXPECTED TO LEAD TO PREDOMINATELY SKC CONDITIONS TONIGHT. //DTW THRESHOLD PROBABILITIES... * MEDIUM IN ISOLATED CLOUD TO GROUND LIGHTNING STRIKES BETWEEN 06- 08Z. * HIGH FOR CIGS BELOW 5000 FT AGL. LOW CONFIDENCE IN POTENTIAL FOR CIGS OF LESS THAN 1000 FT. && .DTX WATCHES/WARNINGS/ADVISORIES... MI...NONE. LAKE HURON...NONE. LAKE ST CLAIR...NONE. MICHIGAN WATERS OF LAKE ERIE...NONE. && $$ SHORT TERM...CB LONG TERM....SF MARINE.......SF AVIATION.....CB 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.