U.S. Hazards Outlook - Made
Jul 01, 2016
|Day 3-7 Outlook
||Day 8-14 Outlook
||Day 8-14 Probabilistic Temperature Hazards
Valid Monday, July 04, 2016 to Friday, July 15, 2016
Summary of Forecasts and Hazards
US Hazards Outlook
NWS Climate Prediction Center College Park MD
EDT July 01 2016Synopsis
: At the beginning of the forecast
period, a stationary front is anticipated to extend from the Central Plains
eastward through the Mid-Atlantic. A surface low pressure system is forecast
to move eastward along this boundary, bringing heavy rainfall to the Ohio
Valley and Mid-Atlantic early in the week-1 period. Mid-level high pressure is
generally forecast for the Western and Central CONUS during week-2. Periodic
weak disturbances are expected to impact Southern Alaska during weeks 1 and 2,
with no associated hazards currently anticipated. Hazards
Summary For Monday July 04 - Friday July 08:
- Heavy rain across portions of the Mid-Atlantic, the Central
Appalachians, and the Ohio Valley, Mon, Jul 4.
- Flooding possible across portions of the Central Plains, Midwest, and Ohio
Valley, Mon-Tue, Jul 4-Jul 5.
- Flooding occurring or imminent across portions of the Southern Plains,
Mon-Tue, Jul 4-Jul 5.
- Excessive heat across portions of South Texas, Mon-Fri, Jul 4-Jul 8.
- Excessive heat across portions of the Central Plains, the Middle
Mississippi Valley and the Midwest, Wed-Fri, Jul 6-Jul 8.
- Excessive heat across portions of the Southeast and Carolinas, Wed-Fri, Jul
- Much above-normal temperatures across portions of the Northern and Central
Plains, Tue-Wed, Jul 5-Jul 6.
- Moderate risk of much above-normal temperatures for portions of the
Southeast, Sat-Sun, Jul 9-Jul 10.
- Slight risk of much above-normal temperatures for portions of the Lower
Mississippi Valley, the Tennessee Valley, the Mid-Atlantic, the Southern
Appalachians, the Southeast, and the Southern Plains, Sat-Mon, Jul 9-Jul 11.
- Slight risk of much above-normal temperatures for portions of the Central
Plains, the Central Rockies, the Central Great Basin, the Southern Rockies, the
Southern Plains, and the Southwest, Tue-Fri, Jul 12-Jul 15.
- Severe Drought across the Central Great Basin, the Northern Plains, the
Tennessee Valley, Hawaii, the Southern Appalachians, the Upper Mississippi
Valley, the Southeast, California, and the Southwest.
At the beginning of the forecast period, 500-hPa ridging is forecast through
the Central CONUS, with adjacent troughing over the Pacific Northwest and New
England. Over the course of week-1, expectations are for the pattern to
progress eastward with ridging becoming established over the eastern half of
the CONUS and troughing across the west, before anticipated flattening of the
flow pattern late in the week. Both the GEFS and ECMWF feature this general
progression over the course of the week, with the GEFS being slightly more
amplified relative to the European solution.
A wave of low pressure moving along a stationary front stretching from the
Central Plains through the Mid-Atlantic will bring a threat of heavy rainfall
(exceeding 1" in 24 hours) shifting eastward from the Ohio Valley through the
Mid-Atlantic on Monday, July 4. Strong to possibly severe thunderstorm
potential also exists with this system for the Central Appalachians on
Independence Day, but no hazard is shown on the map due to predictability
concerns associated with the modest forecast flow amplitude. Flooding is
possible behind this system across portions of the Mid-Mississippi Valley and
To the south of and behind the aforementioned cyclone, ridging is expected
to build with associated heat-related hazards. Excessive heat is forecast
across much of South Texas from Monday, July 4 through Friday, July 8, where
maximum heat index values could exceed 105-115 degrees Fahrenheit due to the
ridge presence coupled with moist low-level flow off the Gulf of Mexico.
Further north, much above-normal temperatures are forecast for parts of the
Northern and Central Plains Tuesday, July 5 and Wednesday, July 6, where
maximum temperature anomalies are anticipated to exceed 12 degrees Fahrenheit
above normal. Another region of excessive heat is forecast for portions of the
Mid-Mississippi Valley, Midwest, and Central Plains on Wednesday, July 6,
through Friday, July 8. Here southerly flow, antecedent rainfall increasing
the soil moisture, and seasonal evapotranspiration in the Corn Belt are
anticipated to help drive heat index values above 105 degrees Fahrenheit. A
final region of excessive heat is forecast across portions of the Southeast and
Carolinas for Wednesday, July 6, through Friday, July 8, where the heat index
could surpass 105-110 degrees Fahrenheit.
Moderate flooding is predicted to continue for the Trinity River at Liberty
near Houston, Texas, at least until July 6th.
Throughout week-1 periodic disturbances are anticipated to impact Southern
Alaska, though none currently justify an associated hazard depiction. For Saturday
July 09 - Friday July 15:
For week-2 the initial 500-hPa flow pattern is
forecast to be relatively flat, although some increases in the amplitude are
anticipated late in week-2 with preferences for ridging in the West and
troughing across the East. The ECMWF also attempts to bring a trough onshore
in the Pacific Northwest early in week-2 that the GEFS keeps further north over
Canada. The strongest ridging during week-2 is anticipated to be established
over the Four Corners region by the middle of the forecast period.
Given the ridging tendencies favored during week-2 across the southern
tier, much above-normal temperatures are possible across the Southern Plains
and Southeast early in week-2. The greatest risk of much above-normal
temperatures is currently from the Central Gulf of Mexico extending North and
East through much of South Carolina during Saturday, July 9 and Sunday, July 10
where the GEFS probabilistic extremes tool gives a greater than 40% chance of
exceeding the 90th percentile of climatological maximum temperatures. With
ensemble guidance forecasting 594 dm ridging across the Four Corners region by
the middle of week-2, a slight risk of much above-normal temperatures exists
for this area through the end of the week-2 period.
According to the U.S. Drought Monitor (USDM), valid on June 28, severe, or
greater intensity, drought covers 4.56 percent of the U.S. Drought Monitor
areas (including Alaska, Hawaii, and Puerto Rico), up slightly from 4.24
percent on June 21.
Forecaster: Daniel Harnos
Click here to see a display of the GFS Ensemble Forecasts
Please consult local NWS Forecast Offices for short range forecasts and region-specific information.