Hail and Damaging Winds in Maryland, June 29, 2019

Area Forecast Discussion
National Weather Service Baltimore MD/Washington DC
301 PM EDT Sat Jun 29 2019

.SYNOPSIS...
A cold front will pass through the area tonight into early
Sunday. High pressure will build offshore for Monday before
settling over the Atlantic during the middle and latter portion
of next week. An upper-level high will build overhead during
this time, causing hot and humid conditions.

&&

.NEAR TERM /THROUGH SUNDAY/...
High pressure remains offshore as of late this afternoon while a
cold front stretches from near Chicago northeastward across
southern Ontario and into New England. Ahead of the front, shear
approaches 30 knots and CAPE has soared well above 2000 j/kg, so
thunderstorms have broken out across much of the region. Biggest
threat is the broken line pushing across southern PA, but
scattered storms further south also pose a threat. A severe
thunderstorm watch is in effect for the DC/Balt metros until 7
PM. Main threat is damaging winds and large hail.

Latest indications suggest that the severe threat will be
focused with ongoing activity, and may wane as we head through
the evening once the CAPE is spent. That said, additional storms
could regenerated closer to the front as it approaches later
this evening into the overnight, so keep some chance POPs until
after midnight. After that, whatever remains should dwindle.
Lows in the 60s to low 70s.

Front may get hung up in central VA early Sunday, which could
cause a stray storm late morning or midday, but rest of the
region should be dry on Sunday. Gradient picking up behind front
will result in a gusty northwest wind, perhaps over 30 mph, and
humidity will be dropping. Highs will be elevated a bit still
thanks to downslope flow, with temps reaching near 90 in many
areas.

&&

.SHORT TERM /SUNDAY NIGHT THROUGH MONDAY NIGHT/...
High pressure builds across the region Sunday night and Monday
with the coolest and least humid day expected Monday. That said,
it will still only be near normal. Winds should be much lighter
however than Sunday. Return flow starts to develop Monday night.
A weak disturbance passing mostly to the north may even spark a
late night shower or storm Monday night, but odds not high just
yet. Will need to watch this potential over the next day or two.

&&

.LONG TERM /TUESDAY THROUGH SATURDAY/...
The long term period will feature an extended stretch of hot
and humid conditions, with daily chances for showers and storms.
Tuesday appears as though it will be the driest day, although a
few afternoon storms can't be ruled out as a weak disturbance
embedded in northwesterly flow moves through. The best chance
for storms on Tuesday will be over the higher terrain in western
portions of the forecast area. High temperatures on Tuesday
will climb into the low 90s for most locations, with dewpoints
in the mid 60s.

The upper level ridge centered over the Southeast US will
strengthen during the Wednesday through Friday time period. This
will lead to weak height rises aloft. A hot and humid airmass
will build underneath the ridge at the surface, and remain in
place through the end of the long term period. Heat indices may
exceed the century mark in places each afternoon Wednesday
through Friday. As weak disturbances pass over the north side of
the ridge and interact with the hot and humid airmass in place,
storms will be possible each afternoon.

&&

.AVIATION /19Z SATURDAY THROUGH THURSDAY/...
Main concern aviation-wise is over the next few hours as
scatterd strong to severe storms cross the region. Highest storm
risk is BWI/MTN, with a bit less near DCA/IAD/MRB and lower
still at CHO, though not zero. Storms should be dwindling by
midnight. Otherwise, VFR expected thru Monday night with a gusty
NW wind (gusts 25-30 knots Sunday afternoon) diminishing at
night and light winds on Monday.

Prevailing VFR conditions are expected through the long term
period. However, brief reductions to sub-VFR conditions will be
possible in association with any thunderstorms that move over
the terminals.

&&

.MARINE...
Approaching cold front this evening will continue to cause
scattered strong to severe thunderstorms, which will necessitate
special marine warnings. These should end towards midnight.
Increasing southerly flow will result in marginal SCA in a few
of the more protected inlets as well, so SCA is out thru the
evening. Cold front will push past early Sunday and will see
widespread SCA gusts by midday Sunday across all waters, perhaps
even a few gusts to 30 knots. Northerly channeling then will
continue thru the night, so SCA continues until early Monday.
May need additional extension, but winds should start
diminishing as gradient relaxes and high builds in.

Sub-SCA level winds are expected on Tuesday and Wednesday. A
few thunderstorms can't be ruled out over the waters on Tuesday,
with higher coverage of thunderstorms anticipated on Wednesday.
Special Marine Warnings may be needed if these storms produce
gusty winds over the waters.

&&

.LWX WATCHES/WARNINGS/ADVISORIES...
DC...None.
MD...None.
VA...None.
WV...None.
MARINE...Small Craft Advisory until midnight EDT tonight for ANZ535-538-
     539.
     Small Craft Advisory from 9 AM Sunday to 6 AM EDT Monday for
     ANZ532>534-537-539>543.
     Small Craft Advisory from 9 AM Sunday to midnight EDT Sunday
     night for ANZ530-531-535-536-538.

&&

SYNOPSIS...RCM
NEAR TERM...RCM
SHORT TERM...RCM
LONG TERM...KJP
AVIATION...RCM/KJP
MARINE...RCM/KJP

Hazardous Weather Outlook
National Weather Service Baltimore MD/Washington DC
209 PM EDT Sat Jun 29 2019

ANZ530>543-DCZ001-MDZ011-013-014-016>018-508-VAZ052>057-301815-
Chesapeake Bay north of Pooles Island MD-
Chesapeake Bay from Pooles Island to Sandy Point MD-
Chesapeake Bay from Sandy Point to North Beach MD-
Chesapeake Bay from North Beach to Drum Point MD-
Chesapeake Bay from Drum Point MD to Smith Point VA-
Tidal Potomac from Key Bridge to Indian Head MD-
Tidal Potomac from Indian Head to Cobb Island MD-
Tidal Potomac from Cobb Island MD to Smith Point VA-
Patapsco River including Baltimore Harbor-
Chester River to Queenstown MD-Eastern Bay-
Choptank River to Cambridge MD and the Little Choptank River-
Patuxent River to Broomes Island MD-
Tangier Sound and the inland waters surrounding Bloodsworth
Island-District of Columbia-Southern Baltimore-Prince Georges-
Anne Arundel-Charles-St. Marys-Calvert-Southeast Harford-
Prince William/Manassas/Manassas Park-Fairfax-
Arlington/Falls Church/Alexandria-Stafford-Spotsylvania-
King George-
209 PM EDT Sat Jun 29 2019

This Hazardous Weather Outlook is for the Maryland portion of the
Chesapeake Bay, Tidal Potomac River, and adjacent counties in
central Maryland and northern Virginia as well as the District of
Columbia.

.DAY ONE...This Afternoon and Tonight

A Severe Thunderstorm Watch is in effect for most of the outlook
area except for King Georges County, Virginia and Saint Marys
County, Maryland until 7 PM. Scattered thunderstorms may produce
damaging wind gusts and large hail this afternoon through this
evening. In addition, thunderstorms may produce heavy rainfall
that lead to isolated instances of flooding.

.DAYS TWO THROUGH SEVEN...Sunday through Friday

No hazardous weather is expected at this time.

.SPOTTER INFORMATION STATEMENT...

Spotter activation is requested for this afternoon and evening.

MDZ003>006-501>507-VAZ025>031-036>040-050-051-501>508-WVZ050>053-
055-501>506-301815-
Washington-Frederick MD-Carroll-Northern Baltimore-
Extreme Western Allegany-Central and Eastern Allegany-
Northwest Montgomery-Central and Southeast Montgomery-
Northwest Howard-Central and Southeast Howard-Northwest Harford-
Augusta-Rockingham-Shenandoah-Frederick VA-Page-Warren-Clarke-
Nelson-Albemarle-Greene-Madison-Rappahannock-Orange-Culpeper-
Northern Fauquier-Southern Fauquier-Western Highland-
Eastern Highland-Western Loudoun-Eastern Loudoun-
Northern Virginia Blue Ridge-Central Virginia Blue Ridge-
Hampshire-Morgan-Berkeley-Jefferson-Hardy-Western Grant-
Eastern Grant-Western Mineral-Eastern Mineral-Western Pendleton-
Eastern Pendleton-
209 PM EDT Sat Jun 29 2019

This Hazardous Weather Outlook is for eastern West Virginia,
northern and central Virginia, and central and western Maryland
with the exception of Garrett County.

.DAY ONE...This Afternoon and Tonight

A Severe Thunderstorm Watch is in effect for the Washington and
Baltimore metropolitan areas, portions of western Maryland and the
easternmost portions of West Virginia until 7 PM. Scattered
thunderstorms may produce damaging wind gusts and large hail this
afternoon and evening, with the highest risk being within the
watch. In addition, thunderstorms may produce heavy rainfall that
lead to isolated instances of flooding.

.DAYS TWO THROUGH SEVEN...Sunday through Friday

No hazardous weather is expected at this time.

.SPOTTER INFORMATION STATEMENT...

Spotter activation is requested for this afternoon and evening.

PRELIMINARY LOCAL STORM REPORT
NATIONAL WEATHER SERVICE BALTIMORE MD/WASHINGTON DC
225 PM EDT SAT JUN 29 2019

..TIME...   ...EVENT...      ...CITY LOCATION...     ...LAT.LON...
..DATE...   ....MAG....      ..COUNTY LOCATION..ST.. ...SOURCE....
            ..REMARKS..

0224 PM     MARINE TSTM WIND 3 ENE DAHLGREN          38.34N  76.99W
06/29/2019  M45 MPH          ANZ536             VA   BUOY

&&

EVENT NUMBER LWX1904889

DH

PRELIMINARY LOCAL STORM REPORT
NATIONAL WEATHER SERVICE BALTIMORE MD/WASHINGTON DC
231 PM EDT SAT JUN 29 2019

..TIME...   ...EVENT...      ...CITY LOCATION...     ...LAT.LON...
..DATE...   ....MAG....      ..COUNTY LOCATION..ST.. ...SOURCE....
            ..REMARKS..

0226 PM     MARINE TSTM WIND 3 ESE DAHLGREN          38.31N  77.00W
06/29/2019  M46 MPH          ANZ536             VA   BUOY

&&

EVENT NUMBER LWX1904890

DH

PRELIMINARY LOCAL STORM REPORT
NATIONAL WEATHER SERVICE BALTIMORE MD/WASHINGTON DC
233 PM EDT SAT JUN 29 2019

..TIME...   ...EVENT...      ...CITY LOCATION...     ...LAT.LON...
..DATE...   ....MAG....      ..COUNTY LOCATION..ST.. ...SOURCE....
            ..REMARKS..

0231 PM     MARINE TSTM WIND 2 SE DAHLGREN           38.31N  77.03W
06/29/2019  M39 MPH          ANZ536             VA   BUOY

&&

EVENT NUMBER LWX1904891

DH

PRELIMINARY LOCAL STORM REPORT...CORRECTED
NATIONAL WEATHER SERVICE BALTIMORE MD/WASHINGTON DC
235 PM EDT SAT JUN 29 2019

..TIME...   ...EVENT...      ...CITY LOCATION...     ...LAT.LON...
..DATE...   ....MAG....      ..COUNTY LOCATION..ST.. ...SOURCE....
            ..REMARKS..

0229 PM     MARINE TSTM WIND 3 ENE DAHLGREN          38.34N  76.99W
06/29/2019  M46 MPH          ANZ536             VA   BUOY

&&

CORRECTED EVENT TIME...EVENT

EVENT NUMBER LWX1904889

DH

PRELIMINARY LOCAL STORM REPORT
NATIONAL WEATHER SERVICE BALTIMORE MD/WASHINGTON DC
242 PM EDT SAT JUN 29 2019

..TIME...   ...EVENT...      ...CITY LOCATION...     ...LAT.LON...
..DATE...   ....MAG....      ..COUNTY LOCATION..ST.. ...SOURCE....
            ..REMARKS..

0236 PM     MARINE TSTM WIND SWAN POINT              38.30N  76.94W
06/29/2019  M40 MPH          ANZ536             MD   BUOY

&&

EVENT NUMBER LWX1904892

DH