The March 2001 East Coast Storm
Storm overview | |
Evolving model & forecaster perspectives | |
Uncertainty & current forecast accuracy | |
HPC’s role & communicating uncertainty | |
Concluding remarks |
The evolving model and
forecaster perspectives
Day 7 (Mon, Feb 26) | |||
High model uncertainty | |||
Northwesterly flow in many model forecasts | |||
HPC – storm moving eastward out to sea | |||
Day 6 (Tue, Feb 27) | |||
Considerable uncertainty in the models | |||
Increased indication of east coast troughing | |||
HPC – potential for east coast storm with heavy snow possible | |||
Day 5 (Wed, Feb 28) | |||
Model uncertainty still high | |||
HPC – potential for east coast storm continues |
The evolving model and
forecaster perspective (cont.)
Day 4 (Thu, Mar 1) | |||
ECMWF ensembles not available | |||
Models starting to converge on development of major cyclone off mid-Atlantic coast (decreasing uncertainty) | |||
HPC – potential for very serious coastal storm for March 4 & 5, including heavy snow & beach erosion | |||
Day 3 (Fri, Mar 2) | |||
Some model runs differ from AVN/MRF on many details of east coast storm | |||
Despite decreasing uncertainty, significant uncertainty remained | |||
HPC – potential for a blizzard with 2 feet of snow | |||
Major pending west coast rain/snow storm | |||
NOAA press release |
The evolving model and
forecaster perspective (cont.)
Day 2 (Sat, Mar 3) | |||
Major increase in model forecast consistency | |||
Model development of the storm slowed | |||
HPC – high confidence for possible
blizzard conditions in mid-Atlantic and the Northeast |
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HPC – decreased likelihood of major snow event for DC to NY | |||
NOAA press conference | |||
Day 1 (Sun, Mar 4) | |||
Good model agreement | |||
Storm forms off the coast of North Carolina |
Day 7
from
Monday,
Feb 26, 2001
Day 6
from
Tuesday,
Feb 27, 2001
Day 5
from,
Wednesday,
Feb 28, 2001
Day 4
from
Thursday,
Mar 1, 2001
Day 3
from
Friday,
Mar 2, 2001
Day 2
from
Saturday,
Mar 3, 2001
Day 1
from
Sunday,
Mar 4, 2001
Uncertainty & current
forecast accuracy
(HPC QPF verification -- 1-inch threat score)
HPC’s Role &
Communicating Uncertainty
Mission statement: to provide forecast, guidance, and analysis products and services 1) to support the daily public forecasting activities of the NWS and its customers, and 2) to provide tailored support to other government agencies in emergency and special situations. |
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Vision statement: to be recognized by the NWS field offices and other forecast groups as a center of excellence for: |
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heavy precipitation forecasting | ||
medium-range forecasting | ||
real-time numerical model diagnostics & interpretation |
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surface analysis |
HPC’s Role &
Communicating Uncertainty
starting point | ||
second opinion | ||
focusing mechanism | ||
unifying influence | ||
emergency backup |
HPC’s Extended Forecast
Discussion
(released Mar 2, 2001, at 3:38 p.m.)
HPC’s Extended Forecast
Discussion
(continued)
HPC’s Extended Forecast
Discussion
(continued)
Very busy forecast period with heavy rains in the SE preceding the Nor’easter, plus major rain event in southern CA. | |||
Events handled well overall, except for east coast megaopolis. | |||
Difficult forecast situation: split flow / blocking | |||
Models indicated east coast storm a week ahead | |||
Given uncertainty in model guidance, very good consistency in HPC storm forecasts day-to-day | |||
Forecast uncertainty apparent in the model runs and mentioned in HPC narrative products | |||
Uncertainty not well perceived by the public | |||
Accuracy of precipitation forecasting has improved significantly, but still much room for improvement | |||
Public expectations increasing faster than forecast accuracy | |||
“Eastern Region Comprehensive Review of
the March 4-7, 2001, Northeast Snowstorm” by NWS Eastern Region staff |
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“March 4-6 East Coast Snowstorm” by Rich Grumm | ||
Doug Berz, HPC | ||
Ed Danaher, HPC | ||
Pete Manousos, HPC | ||
Brett McDonald, HPC | ||
Dave Reynolds, HPC | ||