139
FXUS06 KWBC 191902
PMDMRD
Prognostic Discussion for 6 to 10 and 8 to 14 day outlooks
NWS Climate Prediction Center College Park, MD
300 PM EDT Fri July 19 2024

6-10 DAY OUTLOOK FOR JUL 25 - 29 2024

The mid-level height pattern across North America and the surrounding regions
is beginning to evolve into a more zonal flow pattern across much of the
contiguous U.S. (CONUS). A mid-level ridge over much of the interior western
CONUS at the onset of the period is forecast to deamplify and weak troughing is
likely to develop over portions of the western CONUS. Meanwhile, a stagnant
positively tilted trough across the central CONUS appears to be filling in by
the end of the period. The ECENS, GEFS, and CMCE are all in agreement for an
area of positive 500-hPa height anomalies and associated ridging to develop
across the Upper-Midwest, Great Lakes, and throughout the East by the end of
the period. Over Alaska, positive mid-level height anomalies are forecast at
the onset of the period; however, a pattern change quickly takes hold by days 7
and 8 and near to below-normal 500-hPa heights are forecast for the period.
Near-normal 500-hPa heights are forecast for Hawaii.

The 6-10 day temperature pattern favors above-normal temperatures across the
Interior West ahead of a mid-level trough along the West Coast. This trough
will bring below-normal temperatures to portions of the Pacific Northwest.
Positive 500-hPa height anomalies over the northeastern CONUS are likely to
increase chances for above-normal temperatures across much of the northern-tier
during the 6-10 day period. Below-normal temperatures are likely across the
south-central CONUS and are associated with a weakening positively tilted
trough across the central CONUS. Through the Mid-Atlantic and southern Atlantic
States there remains some disagreement in the evolution of the mid-level height
pattern. This leads some tools to suggest stronger chances for above-normal
temperatures with others forecasting near-normal temperatures, thus a slight
tilt towards above-normal temperatures is forecast. In Alaska, below-normal
temperatures are generally favored across the western Mainland and Southeast
Alaska with good agreement among the dynamical tools. Near to above-normal
temperatures remain favored across eastern portions of the Mainland. In Hawaii,
near-normal temperatures are favored consistent with the dynamical tools.

The 6-10 day outlook favors above-normal precipitation across much of the
eastern CONUS and Southwest. In the Southwest, there continues to be some
chances for above-normal precipitation associated with monsoon activity with
surface high pressure situated over the Four Corners region promoting moisture
advection into the region. A mid-level trough across the West may help to
promote unsettled weather further north into portions of the Great Basin
increasing chances for above-normal precipitation. Further east, a trough and
associated stalled frontal boundary increase chances for above-normal
precipitation from Texas through much of the eastern CONUS. Southerly flow off
the Gulf of Mexico should bring ample moisture through much of the region.
Across the Northern Plains and parts of the northern Rockies, below-normal
precipitation is favored beneath mid-level ridging. In Alaska, above-normal
precipitation is generally favored across much of the state with continued
chances of unsettled weather. In Hawaii, near-normal precipitation is favored
consistent with weak signals and mixed guidance.

The official 6-10 day 500-hPa height blend consists of 10% of Today`s 0z GFS
Ensemble Mean centered on Day 8, 25% of Today`s 6z GFS Ensemble Mean centered
on Day 8, 40% of Today`s 0z European Ensemble Mean centered on Day 8, and 25%
of Today`s 0z Canadian Ensemble Mean centered on Day 8


FORECAST CONFIDENCE FOR THE 6-10 DAY PERIOD: Above-Average, 4 out of 5. Good
agreement among the dynamical tools is offset by differences in temperature and
precipitation patterns across the eastern CONUS.


8-14 DAY OUTLOOK FOR JUL 27 - AUG 02, 2024

At the onset of week-2, an area of troughing is forecast over the western
CONUS, providing relief from above-normal temperatures. This trough is likely
to weaken with time during the period and some of the ensemble guidance begins
to rebuild positive 500-hPa heights into the region by the end of week-2. In
the eastern CONUS, positive 500-hPa height anomalies are forecast over the
Great Lakes and Northeast at the onset of the period and are likely to
overspread much of the East by the middle of week-2. In Alaska, negative
500-hPa height anomalies are forecast across much of Mainland Alaska spreading
from an anomaly center over the Arctic. Over the Aleutian Islands positive
500-hPa heights are favored. In Hawaii, near-normal heights remain forecast for
the state.

The week-2 temperature outlook has elevated chances for above-normal
temperatures across the Northern Plains stretching  through the Great Lakes and
into the Northeast with strong positive 500-hPa height anomalies and mid-level
ridging. Above-normal temperatures are favored more strongly across portions of
the Mid-Atlantic and southern Atlantic states as dynamical tools increase
chances for positive 500-hPa heights along the East Coast. Across the Mountain
West above-normal temperatures are still favored as well ahead of mid-level
troughing along the West Coast and with chances for ridging redeveloping across
the West by the end of week-2.  Near-normal temperatures are favored along the
West Coast beneath this mid-level trough. Lingering below-normal temperature
chances remain forecast for portions of the Southern Plains and Rio Grande
Valley associated with a decaying mid-level trough. For Alaska, guidance is in
good agreement for below-normal temperatures across much of the state beneath a
trough centered across the Arctic. In Hawaii, near-normal temperatures are
favored with weak signals among the various dynamical tools.

Above-normal precipitation remains favored for most areas east of the
Mississippi River extending back into the Southern Plains. These slightly
enhanced chances for above-normal precipitation are associated with a mid-level
trough early in the week-2 period and southerly return flow off the Gulf of
Mexico bringing increased moisture into the eastern CONUS. Near to below-normal
precipitation is favored in portions of the Northern and Central Plains south
into the Four Corners beneath positive 500-hPa height anomalies and a mid-level
ridge. In the Southwest, weak surface high pressure is forecast leading to
reduced chances for monsoon moisture advection into the region. Therefore, near
to below-normal precipitation is favored in these areas today. Above-normal
precipitation remains slightly favored across portions of the Pacific Northwest
in response to onshore flow and mid-level troughing. In Alaska, above-normal
precipitation remains the favored outcome across the state with continued
chances for unsettled weather as forecast by nearly all of the dynamical model
tools. In Hawaii, above-normal precipitation is favored across much of the
state consistent with the tools.

The official 8-14 day 500-hPa height blend consists of: 10% of Today`s 0z GFS
Ensemble Mean centered on Day 11, 25% of Today`s 6z GFS Ensemble Mean centered
on Day 11, 40% of Today`s 0z European Ensemble Mean centered on Day 11, and 25%
of Today`s 0z Canadian Ensemble Mean centered on Day 11


FORECAST CONFIDENCE FOR THE 8-14 DAY PERIOD: Average, 3 out of 5, Good
agreement among the tools offset by a less amplified and transitory height
pattern.

FORECASTER: Ryan Bolt

Notes:


Automated forecasts are issued on Saturday and Sunday. Occasionally manual
intervention is necessary to address quality control and consistency issues. In
these cases, forecasts are manually drawn but a full discussion is not issued.


The notation for the categorical forecast indicated on the maps is the same as
that in the tables: A-above   N-near normal   B-below


The temperature map shows regions with > 33% chance of being warmer (orange,
"A"), colder (blue, "B"), or close to (unshaded, "N"). Historical average
values for the calendar period of the forecast (dashes, "f").  Labels on the
shaded lines give the probability (> 33%) of the more likely category (B or A).
 Probability of N is always < 40%.


The precipitation map shows regions with > 33% chance of being wetter (green,
"A"), drier (tan, "B"), or close to (unshaded, "n"). Historical median values
for the calendar period of the forecast (dashes, "inches").  Labels on the
shaded lines give the probability (> 33%) of the more likely category (B or A).
 Probability of N is always < 40%.


In the southwest and other climatologically dry regions - there will be a
greater than 33.3% chance of no precipitation and occasionally even a normal
(i.e. Median) value of zero - especially during the dry seasons.  In such cases
a forecast of near normal is effectively a forecast of little or no
precipitation.


The climate prediction center uses 1991-2020 base period means as reference in
the climate outlooks.

The next set of long-lead monthly and seasonal outlooks will be released on
August 15.


Analogs to the 5 day mean observed pattern centered 3 days ago (D-3)
for the region from 20N to 70N latitude and 175E to 60W longitude
include the 5 day periods centered on the following dates:
19900710 - 19980706 - 19530710 - 19890714 - 19540703


Analogs to the 7 day mean observed pattern centered 4 days ago (D-4)
for the region from 20N to 70N latitude and 175E to 60W longitude
include the 7 day periods centered on the following dates:
19530710 - 19980707 - 19980801 - 19890716 - 20020711


6-10 DAY OUTLOOK TABLE
Outlook for Jul 25 - 29 2024

STATE      TEMP PCPN   STATE      TEMP PCPN   STATE      TEMP PCPN
WASHINGTON  B    A     OREGON      B    A     NRN CALIF   N    N
SRN CALIF   A    N     IDAHO       A    A     NEVADA      A    A
W MONTANA   A    N     E MONTANA   A    B     WYOMING     A    A
UTAH        A    A     ARIZONA     A    A     COLORADO    A    N
NEW MEXICO  A    A     N DAKOTA    A    B     S DAKOTA    A    B
NEBRASKA    A    B     KANSAS      A    N     OKLAHOMA    B    A
N TEXAS     B    A     S TEXAS     B    A     W TEXAS     B    A
MINNESOTA   A    N     IOWA        A    N     MISSOURI    N    A
ARKANSAS    B    A     LOUISIANA   B    A     WISCONSIN   A    N
ILLINOIS    N    A     MISSISSIPPI B    A     MICHIGAN    A    N
INDIANA     N    A     OHIO        A    A     KENTUCKY    N    A
TENNESSEE   B    A     ALABAMA     B    A     NEW YORK    A    A
VERMONT     A    N     NEW HAMP    A    N     MAINE       A    N
MASS        A    N     CONN        A    N     RHODE IS    A    N
PENN        A    A     NEW JERSEY  A    A     W VIRGINIA  A    A
MARYLAND    A    A     DELAWARE    A    N     VIRGINIA    A    A
N CAROLINA  A    A     S CAROLINA  N    A     GEORGIA     A    A
FL PNHDL    A    A     FL PENIN    A    A     AK N SLOPE  N    A
AK ALEUTIAN B    A     AK WESTERN  B    A     AK INT BSN  B    A
AK S INT    N    A     AK SO COAST B    A     AK PNHDL    B    A



8-14 DAY OUTLOOK TABLE
Outlook for Jul 27 - Aug 02, 2024

STATE      TEMP PCPN   STATE      TEMP PCPN   STATE      TEMP PCPN
WASHINGTON  N    A     OREGON      N    N     NRN CALIF   N    N
SRN CALIF   N    N     IDAHO       A    N     NEVADA      A    N
W MONTANA   A    N     E MONTANA   A    B     WYOMING     A    B
UTAH        A    B     ARIZONA     A    N     COLORADO    A    B
NEW MEXICO  A    N     N DAKOTA    A    B     S DAKOTA    A    B
NEBRASKA    A    B     KANSAS      A    N     OKLAHOMA    N    A
N TEXAS     B    A     S TEXAS     B    A     W TEXAS     A    A
MINNESOTA   A    N     IOWA        A    N     MISSOURI    A    A
ARKANSAS    N    A     LOUISIANA   N    A     WISCONSIN   A    N
ILLINOIS    A    A     MISSISSIPPI N    A     MICHIGAN    A    A
INDIANA     A    A     OHIO        A    A     KENTUCKY    A    A
TENNESSEE   N    A     ALABAMA     A    A     NEW YORK    A    N
VERMONT     A    N     NEW HAMP    A    N     MAINE       A    N
MASS        A    N     CONN        A    N     RHODE IS    A    N
PENN        A    A     NEW JERSEY  A    N     W VIRGINIA  A    A
MARYLAND    A    N     DELAWARE    A    N     VIRGINIA    A    A
N CAROLINA  A    A     S CAROLINA  A    A     GEORGIA     A    A
FL PNHDL    A    A     FL PENIN    A    A     AK N SLOPE  B    A
AK ALEUTIAN B    A     AK WESTERN  B    A     AK INT BSN  B    A
AK S INT    B    A     AK SO COAST B    A     AK PNHDL    B    A

                           LEGEND
TEMPS WITH RESPECT TO NORMAL     PCPN WITH RESPECT TO MEDIAN
A - ABOVE   N  - NEAR NORMAL     A - ABOVE   N - NEAR MEDIAN
B - BELOW                        B - BELOW

THE FORECAST CLASSES REPRESENT AVERAGES FOR EACH STATE. NORMAL
VALUES - WHICH MAY VARY WIDELY ACROSS SOME STATES - ARE
AVAILABLE FROM YOUR LOCAL WEATHER SERVICE FORECAST OFFICE.

FOR ADDITIONAL INFORMATION SEE MESSAGE FXUS06 KWBC - ON AWIPS AS
PMDMRD.

$$