Jump to content
  • Member Statistics

    17,502
    Total Members
    7,904
    Most Online
    Weathernoob335
    Newest Member
    Weathernoob335
    Joined

Heavy Rain/Thunderstorms 4/15-4/16


IsentropicLift

Recommended Posts

TONIGHT THROUGH TUESDAY NIGHT...MODELS HAVE BEEN CONSISTENT
OVER LAST FEW DAYS SHOWING A STRENGTHENING COLD FRONT APPROACHING
AND MOVING ACROSS THE REGION TUESDAY EVENING. LAYER PW HAS ALSO BEEN
CONSISTENT...STILL CONVEYING 1.3 TO 1.5 INCHES...ABOUT 2 STANDARD
DEVIATIONS ABOVE NORMAL FOR THIS TIME OF YEAR...ADDING TO THE
POTENTIAL FOR HEAVY RAIN. THIS GOES ALONG WITH THE INCREASING
MERIDIONAL FLOW FROM THE APPROACHING TROUGH AND UPPER LEVEL JET
ORIENTED SOUTHWEST TO NORTHEAST...TAPPING INTO GULF MOISTURE. THIS
INCREASING MOISTURE ADVECTION IS REFLECTED AS WELL WITH THE LOW
LEVELS...WHICH WILL HAVE AN INCREASE IN STRATUS AND/OR FOG TONIGHT
INTO TUESDAY MORNING. THE FOG COULD POTENTIALLY BE DENSE AS
DEWPOINTS INCREASE AND SEA SURFACE TEMPERATURES WILL STILL BE
RELATIVELY COOL.

THE STRENGTH OF THE PARENT LOW IS NEARLY THE SAME COMPARED TO
PREVIOUS RUNS WITH NEARLY THE SAME MAGNITUDE OF LOW LEVEL JET.
NAM SHOWS 70-80 KT AROUND 900MB TUESDAY AFTERNOON AND EVENING
WHILE GFS SHOWS 60-70 KT. INVERSION WILL LIMIT GUSTS BUT MODERATE
TO HEAVY RAIN MAY HAVE ENOUGH DOWNWARD MOMENTUM TO OVERCOME THE
INVERSION AND BRING A FRACTION OF THIS LOW LEVEL JET TO THE
SURFACE. THERE IS A POTENTIAL HERE FOR HIGHEST GUSTS IN THE 40-55
MPH RANGE WITH HEAVY RAIN WHICH WILL BE MORE PERIODIC IN FREQUENCY.
FOR EXAMPLE...THIS COULD BE OBSERVED WITHIN HEAVIER CELLS
ASSOCIATED WITH A SQUALL LINE JUST AHEAD OF THE COLD FRONT AS IT
MOVES THROUGH. MESOSCALE MODELS ARE POINTING TO THIS SORT OF
STRUCTURE TO RAINFALL BETWEEN MID AFTERNOON TUESDAY AND EARLY
TUESDAY EVENING.

PRECIP BEHIND THE COLD FRONT CONTINUES A TREND TO END AS A
SLEET/SNOW MIX AS COLDER AIR MOVES IN...MAINLY IN THE BOUNDARY
LAYER. PART OF THE ATMOSPHERIC COLUMN BETWEEN 700 AND 850 MB MAY
STILL BE A LITTLE ABOVE FREEZING...HENCE THE POTENTIAL FOR SLEET.
GUSTS WILL BE MORE FREQUENT TOO WITH THE COLD AIR ADVECTION
INCREASING THE MIXING LENGTH TUESDAY NIGHT WITH THE NORTHWEST
FLOW...ALTHOUGH THE GUSTS WILL PROBABLY BE MORE BETWEEN 35-45 MPH
WITH THE DECREASING BOUNDARY LAYER WINDS AS THE LOW LEVEL JET WILL
HAVE MOVED WELL SOUTHEAST OF THE REGION WITH THE FRONT.

IN SUMMARY...THERE WILL STILL BE A WIDESPREAD RAIN EVENT WITH THE
POTENTIAL FOR HEAVY RAIN AT TIMES ALONG WITH A CHANCE OF GUSTY WINDS
AT TIMES WITH THE HEAVIER RAIN AND MORE FREQUENT WITH THE COLD AIR
ADVECTION LATER TUESDAY NIGHT. LATE TUESDAY NIGHT...ENOUGH COLD
AIR COULD MOVE IN FOR LEFTOVER SNOW SHOWERS AND/OR SLEET WITH
LIGHT ACCUMULATIONS POSSIBLE NORTH AND WEST OF NEW YORK CITY. LOW
TEMPERATURES WILL BE NEAR OR BELOW FREEZING LATE TUESDAY NIGHT
INTO VERY EARLY WEDNESDAY MORNING.
 

Link to comment
Share on other sites

  • Replies 73
  • Created
  • Last Reply

Am I crazy or does the gfs and nam indicate some snow before the precip ends west of the city even into central nj?

The Nam especially looks like it brings in the cold faster than the gfs, of course it is the Nam.

That would be pretty amazing to see this late in the season especially after several days of 70s and 80s.

Link to comment
Share on other sites

Am I crazy or does the gfs and nam indicate some snow before the precip ends west of the city even into central nj?

The Nam especially looks like it brings in the cold faster than the gfs, of course it is the Nam.

That would be pretty amazing to see this late in the season especially after several days of 70s and 80s.

Read the bolded post in April discussion
Link to comment
Share on other sites

Am I crazy or does the gfs and nam indicate some snow before the precip ends west of the city even into central nj?

The Nam especially looks like it brings in the cold faster than the gfs, of course it is the Nam.

That would be pretty amazing to see this late in the season especially after several days of 70s and 80s.

You should check out the Euro then.

Link to comment
Share on other sites

I wonder if the models are struggling today with the positioning of cold front and the LLJ. For example it's currently almost 15z. The 12z NAM's depiction says that by 18z virtually no rain has fallen in the Delmarva in the past six hours yet it's currently pouring in that region. Then it doesn't have the real heavy precip into southeast Virginia until after 18z yet that area is currently getting blasted by heavy convection.

Link to comment
Share on other sites

Western CT has been getting hit by a persistent band ahead of the main band, already .40 here with the main show to come.

Yeah I don't think the models are going to bust badly on this one but areas should easily pick up over an inch except in isolated areas that manage to miss the heaviest bands.

Link to comment
Share on other sites

Archived

This topic is now archived and is closed to further replies.

  • Recently Browsing   0 members

    • No registered users viewing this page.

×
×
  • Create New...