Michael L. Jurewicz, Sr. WFO Binghamton, NY Northeast Regional
Operational Workshop November 5, 2009
Slide 2
AR TC Tracks and PRE Locations All AR TC TracksAll AR PPTC
Tracks; with PRE centroids (colored dots)
Slide 3
Mid-level Streamlines Representative TC Tracks TC Rainfall PREs
LL e -Ridge Axis See inset UL Jet Conceptual Model: LOT PREs Ahead
Of SR Or AR TCs Revised and updated from Fig. 13 of Bosart and Carr
(1978)
Slide 4
Bill
Slide 5
Brief History of Bill Himself Bill was initially a Cape Verde
tropical wave, which became a named storm on 15 August From 19-23
August, Bill attained hurricane status well off the U.S. East Coast
(briefly reached Category 3) From 23-25 August, Bill transitioned
to an extra- tropical system, as it recurved into the westerlies
southeast of the Canadian maritime provinces
Slide 6
Bills Approximate Path
Slide 7
Heavy Rainfall Event across New England
Slide 8
Afternoon Rainfall on 22 August Up to 7 (175 mm) rainfall
700 mb Heights, 925 mb Winds/Theta-E, at 21z, 22 August Near
intersection of Bills moisture and pre-existing moist plume
Slide 18
Parcel Trajectories into Central New England Bills Track
Slide 19
Bill Summary Bill fit into the AR track for potential
PRE-producing systems One main heavy rain episode took place on the
periphery of Bills influence Southern NH on 22 August 4-7 (up to
175 mm) of rain fell within just a few hours, causing flash
flooding Transient nature of heavier rain bands precluded excessive
rainfall/runoff problems elsewhere
Slide 20
Danny
Slide 21
Brief History of Danny Himself Danny was initially a Cape Verde
tropical wave, and took several days to become a named storm
Finally, on 26 August, it attained Tropical Storm status east of
the Bahamas From 26-29 August, Danny remained a Tropical Storm well
off the Southeast U.S. coast From 29-31 August, Danny weakened to a
Tropical Depression, and ultimately transitioned to an extra-
tropical system, as it recurved off the U.S. East Coast
Slide 22
Dannys Approximate Path
Slide 23
Heavy Rainfall Event across the Mid-Atlantic Region
Slide 24
Late Night/Early Morning Rainfall, 27-28 August 4-8 (100- 200
mm) rainfall
Slide 25
Radar Loop
Slide 26
250 mb at 00z, 28 August
Slide 27
Water Vapor Loop
Slide 28
700 mb Heights, 925 mb Winds/Theta-E, at 05z, 28 August Axis of
tro pical moisture Separate moist axis
Slide 29
850 mb at 00z, 28 August
Slide 30
Parcel Trajectories into the Mid- Atlantic Region
Slide 31
200 mb Height/Jet/PV, 02z, 28 August
Slide 32
200 mb Height/Jet/PV, 09z, 28 August
Slide 33
SB CAPE Analysis, 06z, 28 August
Slide 34
Heavy Rainfall Event Just off the Mid-Atlantic Coast
Slide 35
Late Afternoon/Overnight Rainfall, 28-29 August Widespread 5-10
(up to 250 mm) rainfall
Slide 36
Radar Loop, 28-29 August
Slide 37
250 mb at 00z, 29 August
Slide 38
Water Vapor, 28-29 August
Slide 39
700 mb Heights, 925 mb Winds/Theta-E, at 03z, 29 August
Tropical Moisture Axis
Slide 40
SB CAPE Analysis, 00z, 29 August Possible PRE
Slide 41
Surface Analysis, 00z, 29 August Possible PRE
Slide 42
850 mb Analysis, 00z on 29 August
Slide 43
Parcel Trajectories into the Mid- Atlantic Coastal Region
Dannys Track
Slide 44
Danny Summary Danny fit into the AR track for potential
PRE-producing systems Two distinct heavy rain episodes took place
on the periphery of Dannys influence Event that most resembled a
PRE took place just offshore, 28- 29 August Heavy rain/flash
flooding that occurred in the Baltimore area appeared to lack
sufficient moisture contributions from Danny or jet interactions
Lack of a direct moisture connection with the TC, as well as a
relatively cool stable air mass, seemed to protect much of the
Northeastern U.S. from excessive rainfall
