696
FXUS10 KWNH 070658
PMDHMD
MODEL DIAGNOSTIC DISCUSSION
NWS WEATHER PREDICTION CENTER COLLEGE PARK MD
157 AM EST FRI FEB 07 2020
VALID FEB 07/0000 UTC THRU FEB 10/1200 UTC
...SEE NOUS42 KWNO (ADMNFD) FOR THE STATUS OF THE UPPER AIR
INGEST...
00Z MODEL EVALUATION WITH LATEST MODEL PREFERENCES AND CONFIDENCE
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
..PHASING TROUGHS OVER THE MID-ATLANTIC/NORTHEAST ON FRIDAY
..POWERFUL SURFACE LOW CENTER ADVANCING THROUGH THE NORTHEAST
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
PREFERENCE: GENERAL MODEL BLEND
CONFIDENCE: ABOVE AVERAGE
THE MODELS REFLECT NORTHERN STREAM ENERGY CURRENTLY OVER PORTIONS
OF THE UPPER GREAT LAKES AND MIDWEST THAT WILL DIG SOUTHEAST AND
PHASE ON FRIDAY WITH THE STRONG EJECTING SOUTHERN STREAM TROUGH
OVER THE TN VALLEY AND GULF COAST STATES. THE PHASING OF THESE
SYSTEMS WILL LEAD TO A CONSOLIDATED, BUT VERY POWERFUL AREA OF LOW
PRESSURE OVER THE INTERIOR OF THE MID-ATLANTIC AND ESPECIALLY NEW
ENGLAND BY LATE IN THE DAY. IN FACT, LOCALLY IN A FEW SPOTS ACROSS
THE NORTHEAST, IT IS EXPECTED THAT THERE WILL BE ALL-TIME LOW
SURFACE PRESSURE RECORDS SET FOR THE MONTH OF FEBRUARY. THIS LOW
CENTER WILL THEN EXIT VERY QUICKLY NORTHEAST THROUGH THE CANADIAN
MARITIMES FRIDAY NIGHT AND EARLY SATURDAY. MODEL SPREAD IS VERY
MODEST, SO A GENERAL MODEL BLEND WILL BE PREFERRED.
..SHORTWAVE CROSSING THE PLAINS AND OH VALLEY BY SATURDAY
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
PREFERENCE: NON-NAM BLEND
CONFIDENCE: ABOVE AVERAGE
STRONG FLOW WILL CONTINUE TO OVER-TOP A BROAD BUT DOMINANT EASTERN
PACIFIC/WEST COAST RIDGE AXIS THROUGH FRIDAY WHICH WILL ALLOW
SUBTLE SHORTWAVE ENERGY CRESTING THE RIDGE TO DIVE SOUTHEAST
ACROSS THE CENTRAL/NORTHERN PLAINS BY FRIDAY EVENING AND THEN
ACROSS THE OH VALLEY ON SATURDAY. A WEAK AREA OF SURFACE LOW
PRESSURE AND A FRONT WILL BE ASSOCIATED WITH THIS ENERGY. THE 00Z
NAM IS A TAD SLOWER AND OCCASIONALLY A LITTLE DEEPER THAN THE
GLOBAL MODELS AS THE ENERGY TRAVERSES THE MIDWEST. THE 00Z UKMET
HAS TRENDED IN LINE WITH THE REMAINING GLOBAL MODEL SUITE. SO,
WILL PREFER A NON-NAM BLEND WITH THIS SYSTEM AT THIS POINT.
..DEEP TROUGH/CYCLONE CROSSING THE PACIFIC NORTHWEST SATURDAY
..DIGGING ENERGY OVER THE GREAT BASIN/SOUTHWEST BY SUNDAY
..DOWNSTREAM TROUGHING OVER THE NORTHERN PLAINS BY SUNDAY
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
PREFERENCE: BLEND OF THE 00Z GFS/ECMWF
CONFIDENCE: SLIGHTLY ABOVE AVERAGE
A STRONG CLOSED LOW WILL ADVANCE THROUGH THE ALEUTIAN ISLANDS AND
AK PENINSULA BY EARLY FRIDAY, WITH STRONG SHORTWAVE ENERGY THEN
DIGGING QUICKLY SOUTHEAST TOWARD BRITISH COLUMBIA AND THEN ACROSS
THE PACIFIC NORTHWEST FRIDAY NIGHT THROUGH EARLY SATURDAY. BY
SUNDAY, A PORTION OF THIS INITIAL SURGE OF ENERGY WILL QUICKLY
EJECT DOWNSTREAM ACROSS THE NORTHERN ROCKIES AND OVER THE NORTHERN
PLAINS. MEANWHILE, A SPLIT IN THE UPPER FLOW WILL ALLOW FOR A
SUBSTANTIAL AMOUNT OF ENERGY TO THEN DIG SOUTHWARD OVER THE GREAT
BASIN AND INTO THE SOUTHWEST AROUND THE EASTERN SIDE OF A STRONG
DEEP LAYER RIDGE DEVELOPING OFFSHORE THE WEST COAST THIS WEEKEND.
THE 00Z UKMET HAS TRENDED NOTABLY SLOWER COMPARED TO ITS PREVIOUS
RUN AND IS IN BETTER AGREEMENT WITH THE MULTI-MODEL CONSENSUS AS
THIS ENERGY ARRIVES ACROSS THE PACIFIC NORTHWEST, AND ALSO TO A
LARGE EXTENT WITH THE SPLIT FLOW EVOLUTION THEREAFTER AS ENERGY
BREAKS AWAY AND DROPS INTO THE SOUTHWEST. BY LATER SUNDAY, THE
UKMET IS STILL PERHAPS A LITTLE TOO FAST IN SWINGING THE ENERGY
DOWN ACROSS SOUTHERN CALIFORNIA, BUT THE TREND APPEARS FAVORABLE.
MEANWHILE, THE NORTHERN STREAM ENERGY BREAKING AWAY AND CROSSING
THE PLAINS AND UPPER MIDWEST THROUGH SUNDAY WILL BE ACCOMPANIED BY
A WAVE OF LOW PRESSURE AND A NEW FRONTAL ZONE. THE 00Z NAM
GRADUALLY BECOMES A LITTLE SLOWER THAN THE GLOBAL MODELS AT THE
SURFACE, AND AT LEAST ALOFT MAY BE A TAD TOO DEEP. THE 00Z UKMET
FOR ITS PART IS NOW IN LINE WITH THE REMAINING MODEL GUIDANCE.
OVERALL, THE 00Z GFS AND 00Z ECMWF HAVE THE BEST MODEL CLUSTERING
AND ENSEMBLE SUPPORT, SO A BLEND OF THESE SOLUTIONS WILL BE
PREFERRED WITH THE ENERGY AS IT ARRIVES ACROSS THE NORTHWEST, AND
THEN ALSO WITH THE SPLIT FLOW EVOLUTION THEREAFTER.
MODEL TRENDS AT WWW.WPC.NCEP.NOAA.GOV/HTML/MODEL2.HTML
500 MB FORECASTS AT WWW.WPC.NCEP.NOAA.GOV/H5PREF/H5PREF.SHTML
ORRISON
CLICK HERE TO GO TO PREVIOUS BULLETINS.
Main Text Page