Forecast Discussions mentioning "ACARS", "MDCRS", or "AIRCRAFT" received at FSL on 04/03/02

...MAIN QUESTION FOR THIS CYCLE WILL BE TEMPERATURES...

THE 12Z DIAGNOSTICS INDICATE THE NORTHERN BRANCH COLD FRONT NOW WELL CLEAR OF THE FORECAST AREA HAVING REACHED THE RED RIVER AND THE TEXAS BIG BEND AREAS WHILE THE DYNAMIC LOW MOVES EAST ACROSS THE UPPER OHIO VALLEY STATES. H5 AND H7 THERMAL ANALYSIS INDICATE SEVERAL EMBEDDED AND FAST MOVING SHORT WAVE TROUGHS IN THE UPPER LEVEL BAROCLINIC ZONE WHICH EXTENDS FROM THE PACIFIC NORTHWEST THROUGH THE CENTRAL PLAINS AND OFF SHORE OVER NEW ENGLAND. MOISTURE ALONG THE BAROCLINIC ZONE HAS BEEN TOO SPARSE TO SUPPORT MUCH PRECIPITATION OVER THE HIGH PLAINS REGION. FARTHER SOUTH THE ACTIVE SOUTHERN BRANCH CONTINUES ACROSS THE LOWER BAJA EASTWARD THROUGH SOUTHERN FLORIDA. A NUMBER OF PROGRESSIVE SHORT WAVE TROUGHS ALOFT CONTINUE ALONG THIS FEATURE. GULF MOISTURE AVAILABLE TO THESE SHORT WAVES HAD ALLOWED PRODUCTION OF CLOUDS AND PRECIPITATION OVER FLORIDA AND OVER TEXAS WITH SEVERAL MORE UPSTREAM WAVES ACROSS THE EASTERN PACIFIC STILL TO MOVE EAST ACROSS MEXICO AND INTO THE GULF.

MODEL MASS FIELDS TODAY APPEAR TO HAVE ONCE AGAIN INITIALIZED QUITE WELL WITH 6 HOURS FORECASTS OFF THE 12Z MODELS VERIFYING WELL COMPARED TO AIREPS, ACARS AND SATELLITE IMAGERY. THE UPPER LOW OVER THE EASTERN PACIFIC APPEARS TO BE SHEARING OUT MUCH AS ADVERTISED FOR THE PAST SEVERAL MODEL RUNS AND IT HAS BEEN WELL SAMPLED IN THE DATA FIELDS. IN THE MOISTURE FIELDS THE MODELS AGAIN APPEAR TO HAVE INITIALIZED WELL BUT THERE ARE SIGNIFICANT DIFFERENCES IN THEIR HANDLING OF THE LOW LEVEL MOISTURE FIELDS OVER THE HIGH PLAINS IN THE LATE PERIODS. ALL OF THEM DEVELOP A DEEPENING LEE CYCLONE OVER SOUTHEAST COLORADO BY THURSDAY MORNING IN RESPONSE TO THE UPSTREAM SHORT WAVE TROUGH ALOFT IN THE NORTHERN BRANCH BAROCLINIC ZONE NOW OVER WESTERN CANADA. INCREASING SOUTHERLY SURFACE WINDS WITH THIS FEATURE AND WARMER TEMPERATURES MAKE SENSE, BUT THE NGM AND AVN PUMP GULF MOISTURE NORTHWARD INTO THE REGION ON THIS FLOW IN APPARENT DISREGARD OF THE SOUTHERN BRANCH BAROCLINIC ZONE ACROSS THE GULF. THE ETA IS CONSIDERABLY DRIER IN LOWER LEVELS AND WILL THUS BE USED FOR THE LATE PERIODS OF THIS FORECAST.

TEMPERATURES WILL DEPEND LARGELY UPON THE AMOUNT OF HIGH LEVEL MOISTURE AVAILABLE IN THE UPPER BAROCLINIC ZONE AND THE RESULTANT CLOUD PRODUCED BY THE BAROCLINIC ZONE AND BY MOUNTAIN ENHANCEMENT OFF THE ROCKIES. SUN ANGLES ARE GETTING FAIRLY HIGH THUS AREAS WHERE MUCH SUNSHINE IS SEEN SHOULD WARM NICELY. THE DEVELOPMENT OF A LEE CYCLONE IN SOUTHEAST COLORADO THURSDAY SHOULD BRING WARMEST TEMPERATURES IN MY FAR SOUTHWEST ZONES AND WILL GO A BIT ABOVE THE GUIDANCE THERE THOUGH HIGH LEVEL CLOUDS, IF THEY MATERIALIZE COULD THROW A WRENCH INTO THE WORKS. A SWATCH OF CIRRUS CURRENTLY MOVING ONSHORE OVER THE PACIFIC NORTHWEST SHOULD REACH THE AREA BY WEDNESDAY MORNING BUT THE AMOUNT AND EXTENT OF CLOUD WITH THIS FEATURE IS NOTHING MORE THAN A GUESS AT THIS TIME. FOR NOW WILL GO FOR WEDNESDAY AND THURSDAY HIGHS A BIT ABOVE THE COOLER FWC BUT BELOW THE WARMEST MAV. LOWS TONIGHT SHOULD DIP NICELY INTO THE TEENS AND WILL GO JUST BELOW THE GUIDANCE. ALSO BELIEVE THE FWC IS TOO WARM FOR WEDNESDAY NIGHT.

DAYS 3-7... MAIN CHALLENGE IN THE EXTENDED IS PRECIPITATION CHANCES AROUND DAY 4. DIAGNOSTIC DATA AGAIN SHOW NO CLEAR SIGNALS PER OLR HOVMOLLER AND ANGULAR MOMENTUM CHARTS BUT MODELS ARE IN FAIRLY GOOD AGREEMENT. LOBE OF POLAR VORTEX OVER EASTERN CANADA GET SHUNTED EAST IN THE FAIRLY PROGRESSIVE PATTERN AND ALLOWS RIDGING TO DEVELOP OVER THE CENTRAL CONUS TOWARD DAY 7 AS HEIGHTS FALL OVER ALASKA. IN THE MEAN TIME, ENERGY AROUND 30N 150W TODAY EVIDENT ON WATER VAPOR IMAGERY TO SLIDE EAST INTO THE CONUS FRIDAY AND CONTINUE INTO THE PLAINS SATURDAY AND SUNDAY. WV LOOP ALSO SHOWING ACTIVE SOUTHERN BRANCH PER ABOVE DISCUSSION. THE AFFECT OF THE SOUTHERN BRANCH TO PLAY A MAJOR ROLE IN WHETHER ENOUGH LOW LEVEL MOISTURE WILL BE AVAILABLE FOR THE SHORTWAVE TROF TO PRODUCE PRECIPITATION IN SOUTHWEST KANSAS. ALONG WITH PREVIOUS SHIFTS, WOULD TEND TO THINK MOISTURE WILL HAVE A DIFFICULT TIME NOT BEING WRUNG OUT IN CLOUD OR PRECIPITATION FORM TO THE SOUTH AND BE ABLE TO BRING THE LIKE HERE SO WILL LEAVE SATURDAY DRY FOR NOW.

AS FOR TEMPERATURES, CURRENT WARMING TREND FOR FRIDAY AND SATURDAY MAY BE A BIT OVERZEALOUS BUT WON'T CHANGE IT MUCH. PACIFIC AIRMASS TO BE WELL MODIFIED FOR SUNDAY AND EXPECT ONLY A RETURN TO NEAR NORMAL. RISING HEIGHTS ALOFT SHOULD RETURN TEMPERATURES TO WELL ABOVE NORMAL BY DAY 7.

PRELIMINARY GUIDANCE FOR COORDINATION ONLY. OFFICIAL FORECASTS ARE CONTAINED WITHIN THE DODGE CITY ZONE FORECAST.

DDC 17 46 26 54 / 0 0 0 0 GCK 15 47 24 57 / 0 0 0 0 EHA 20 49 30 61 / 0 0 0 0 LBL 18 48 28 59 / 0 0 0 0 HYS 16 44 23 49 / 0 0 0 0 P28 23 46 28 54 / 0 0 0 0

.DDC...NONE.

JOHNSON/POAGE



MARINE LAYER DEPTH ON THE RISE OVERNIGHT...LAPPING AT THE LOWER COASTAL SLOPES AND EVEN SPILLING INTO THE CUYAMA VALLEY JUST AFTER MIDNIGHT. THE WEAK UPPER LOW SW OF POINT CONCEPTION IS KEEPING ENOUGH CYCLONIC SPIN TO THE ATMOSPHERE TO HELP MAINTAIN A HEALTHY STRATUS DECK THUS FAR. A SPOTTER PHONED IN A DRIZZLE REPORT FOR A FEW VALLEY LOCALES EARLIER...AND MORE IS EXPECTED THROUGHOUT THE MORNING ACROSS VALLEYS/FOOTHILLS AND LOWER COASTAL SLOPES. AS FOR BURNOFF TODAY... EARLY AM ACARS SUGGEST INVERSION STRENGTH HAS WEAKENED BY A COUPLE OF DEGREES...BUT WITH ONSHORE GRADIENTS RUNNING IN THE 5 TO 8 MB RANGE AND BELOW NORMAL SSTS TODAY...EXPECT ANOTHER DAY OF SLUGGISH CLEARING AND COOL TEMPS. A FEW CU'S FORMED OVER THE VTU/SBA MOUNTAINS LATE YESTERDAY...AND WITH THE AMOUNT MID LEVEL MOISTURE AROUND...AFTERNOON HEATING SHOULD PRODUCE A FEW MORE OVER THE MOUNTAINS THIS AFTERNOON.

CROSS SECTIONS INDICATE THURSDAY MAY SEE BETTER CLEARING DUE TO A MUCH WEAKER INVERSION WHICH SHOULD BETTER FOSTER MIXING. WHILE NOT MUCH CHANGE TO VALLEY/DESERT/MOUNTAIN TEMPS IS EXPECTED...COASTAL LOCATIONS MAY SEE SOME SUNLIGHT THURSDAY AFTERNOON AND A COUPLE OF DEGREES WARMUP. UPPER LOW OFF THE COAST OPENS UP AND IS NUDGED OVER SOCAL THURSDAY PM BY A SLIGHTLY STRONGER SYSTEM TO THE WEST. THIS WILL REESTABLISH THE LOW CLOUDS...FOG...AND DRIZZLE THURSDAY NIGHT. HAVE PUT SOME THOUGHT INTO THE POSSIBILITY OF CONVECTIVE BUILDUPS OVER THE MOUNTAINS THURSDAY AFTERNOON WITH THE COMBINATION OF MID LEVEL MOISTURE...AFTERNOON HEATING...AND A SHORTWAVE OVERHEAD...BUT WILL STICK TO PARTLY CLOUDY WORDING FOR NOW AND SEE WHAT HAPPENS TODAY. AVN TAKES THE LATTER AND STRONGER TROUGH OVER THE DISTRICT FRIDAY THROUGH EARLY SATURDAY MORNING. THIS SCENARIO PRODUCES THE BEST CHANCE AT LIGHT RAINFALL...BUT WITH MAIN DYNAMICS APPARENTLY TO THE SOUTH...WILL STICK WITH DRIZZLE WORDING AND LEAVE POPS OUT OF THE FORECAST FOR NOW. AT ANY RATE...SYSTEM PROGGED TO MOVE THROUGH QUICKLY...WITH NORTHERLY FLOW IN ITS WAKE HELPING TO CLEAR THINGS OUT SATURDAY AFTERNOON.

RIDGE BUILDS OVER SOCAL LATE SATURDAY INTO FIRST HALF OF NEXT WEEK FOR A RETURN TO A...ALBEIT LESS EXTENSIVE...MARINE LAYER REGIME. SEVERAL DEGREES WARMUP EXPECTED FROM THE VALLEYS INLAND...WITH MORE SUBDUED INCREASES COASTSIDE.

LAX 000. TANABE.

.LOX...NONE.



.SYNOPSIS...A PERSISTENT MARINE LAYER WILL CONTINUE TO BRING EXTENSIVE NIGHT AND MORNING LOW CLOUDS AND FOG TO AREAS WEST OF THE MOUNTAINS INTO NEXT WEEK. A WEAK UPPER TROUGH OF LOW PRESSURE MOVING INLAND ACROSS SOUTHERN CALIFORNIA WILL BRING SOME COOLING AND LOCALLY GUSTY WINDS TO INLAND AREAS FRIDAY. WARMER AND CONTINUED DRY FOR SATURDAY INTO NEXT WEEK AS WEAK HIGH PRESSURE BUILDS OVER SOUTHERN CALIFORNIA.

.DISCUSSION...ONLY MINOR ADJUSTMENTS MADE TO THE PREVIOUS FORECAST...MAINLY MINOR ADJUSTMENTS TO TEMPERATURES. TUE EVENING ACARS SOUNDINGS SHOWED THE BASE OF A STRONG MARINE INVERSION NR 2500 FT WITH THE INVERSION TOP NR 3000 FT. ETA SHOWS LTL CHANGE FOR THE NEXT TWO NIGHTS...XCP COOLING ALF THU NIGHT THRU FRI NIGHT SHOULD WKN THE INVERSION SOME. MOST MDLS XCP FOR THE ECMWF ARE NOW SIMILAR TO LAST NIGHTS AVN SOLUTION WITH THE AVN/MRF FOLLOWED THRU THE EXTENDED.

THE WK UPR LOW OFF THE SRN CA CST WL WKN AND MOVE ONSHR THU NIGHT... NUDGED E BY A STRONGER UPSTREAM TROUGH THAT THE AVN MOVES INLAND ACROSS NRN BAJA FRI NIGHT. FRI SHOULD BE THE COOLEST DAY INLAND. THE WK UPR LOW MOVG INLAND THU NIGHT MIGHT SQUEEZE OUT A LTL DRIZZLE...SO PATCHY DRIZZLE WORDING WAS RETAINED. THE UPR TROUGH MOVG INLAND ACROSS NRN BAJA FRI NIGHT MIGHT ALSO SQUEEZE OUT A LTL DRIZZLE OR LIGHT RAIN LATE FRI NIGHT INTO EARLY SAT. FOR NOW...THE CURRENT DRY WORDING WAS RETAINED. FOLLOWING PASSAGE OF THE TROUGH... WK UPR RDGG BUILDS ACROSS SRN CA FOR SAT INTO EARLY NEXT WK WITH A MDT WARMUP INLAND AND A CONTINUED MARINE INFLUENCE W OF THE MTNS... BUT WITH PERHAPS A LTL GREATER AND FASTER DAYTIME CLRG.

.SAN...NONE.

MARTIN



ZONES IN FINE SHAPE FOR NO UPDATES NEEDED. MORNING SOUNDING AND LATEST ACARS NEAR BOISE SUGGEST AFTERNOON MIXING TO 710-15 MBS WITH VALLEY HIGHS 62-68 AND LIGHT LOW LAYER WINDS...TO 20KTS MIXING LYR. LATEST RUC SHOWING DECREASING LOW LAYER MOISTURE IN CENTRAL MTNS FOR ONLY FEW-SCT AFTN HIGH BASED CU. WITH CLEAR SKIES AND APRIL SUNSHINE AND INCREASING FREEZING LEVELS WILL CONTINUE TO SEE WARMING TREND IN THRUT AREA LEADING TO CONTINUED SNOW MELT OF LAST FEW WEEKS, WITH VIS IMAGERY SNOW REFLECTION AREAS SHRINKING.

NEW ETA FOR THURSDAY AFTERNOON SHOWS INCREASE IN MID LAYER RH TO 60 PCT SRN HARNEY COUNTY WHERE LIS FALL BELOW ZERO...SUPPORTING ISOLATED TSTMS AS IN CURRENT PACKAGE. BY MID DAY FRIDAY ATMOSPHERE MOISTENS UP MORE WITH ISOLD-SCT SHOWERS AND TSTMS IN ERN OREGON THRU SW IDAHO. FOR FRIDAY AFTERNOON THE 60HR ETA EVEN SHOWS 400 CAPE ON THE ORE-IDA BORDER WITH LIGHT-MDT WSW WINDS ALOFT FOR ONLY WEAK SHEAR. CURRENT PACKAGE GENLY IN LINE WITH THE 12Z RUNS FOR NO UPDATES.

.BOI...NONE.