September 27, 2022: 48-Hour Weather Report and Intermediate-Term Outlooks; Tropical

Here is what we are paying attention to this evening and the next 48 hours from this afternoon’s NWS Forecast.

...Hurricane Ian is forecast to make landfall on the west coast of Florida
late Wednesday; slow forward motion of Ian will likely prolong impacts
from high winds, heavy rain, and flooding even for areas further inland...

...Cool weather expected to persist across the Northeast and Great Lakes
through at least mid-week...

...Well above average temperatures across much of the West, with excessive
heat continuing over parts of southern California, followed by arrival of
rain and cooler temperatures over the Pacific Northwest later on
Wednesday...

Continuation of the NWS Short Range Forecast (It is updated twice a day and these updates can be found here.

Hurricane Ian continues to re-intensify as it pulls away from Cuba and
begins its approach towards the western coast of Florida. The latest NHC
forecasts depict the storm moving northward this evening, bypassing the
Florida Keys to the west before making landfall as a major hurricane
tomorrow evening south of Tampa Bay, FL. With the storm just 100 miles
southwest of Key West, outer bands of Hurricane Ian have already begun
impacting much of southern Florida, with heavy rain ongoing. As Ian
continues its northward progression, winds will begin to increase to
hurricane force along coastal portions of Florida. Ian is forecast to slow
down its forward motion as it begins to interact with a stationary front
settling across northern Florida.  This interaction will likely prolong
the threat of heavy rain and high winds near and to the northeast of where
Ian makes landfall.  How fast/slow Ian moves will partly depend on how
fast/slow an amplified upper trough retreats into eastern Canada as well
as how fast/slow Ian interacts with the front. As a result of the heavy
rain and slow movement speed, a Moderate Risk of Excessive Rainfall is in
place for southern FL in the Day 1 timeframe, with a High Risk of
Excessive Rainfall being hoisted in the Days 2 & 3 timeframes across much
of FL. As heavy rain falls on top of already wet grounds, widespread
instances of flooding are expected. In addition to the rainfall threat,
the Storm Prediction Center has included central and southern FL in a
Slight Risk for Severe Thunderstorms through Thursday due to the threat of
tornados. The combination of life-threatening storm surge, and
hurricane-force winds, in addition to the likelihood of flooding
associated with heavy rainfall, will lead to a very dangerous situation
across central and southern Florida through Thursday as Hurricane Ian
makes landfall.

Elsewhere, cool, fall-like temperatures will continue across the Midwest
and Northeast through Thursday as a deep, upper-level trough moves
eastward. Most of the Upper Midwest, Great Lakes, and interior Northeast
will see highs in the upper-50s and low-60s through Thursday. Freeze
Warnings have been issued for portions of the northern Great Lakes region,
with Frost Advisories also in effect in the Upper Mississippi Valley as
Wednesday morning lows will bottom out in the mid-30s.  Southern portions
of the Midwest as well as the coastal Northeast will see highs in the
mid-60s to low 70s. Temperatures across the Southeast will cool from the
upper 70s/low 80s today to the mid-70s Wednesday and Thursday. Conditions
are forecast to remain fairly dry across the region, outside of areas
along the Lake Erie and Ontario shorelines in interior NY & PA, as strong
winds blowing cool air over the warm lakewater will lead to heavy
lake-effect rainfall through this evening. As a result, a Slight Risk for
Excessive Rainfall has been hoisted along the Lake Ontario shoreline in
western NY.

Further west, above-average temperatures will remain over the region as a
strong upper-level ridge moves eastward. Temperatures are forecast to soar
into the 100s and 90s for the desert southwest and interior southern
California, leading to the issuance of Excessive Heat Warnings and Heat
Advisories in the Los Angeles and San Diego metro areas through Wednesday
evening. By late Wednesday, moisture ahead of a Pacific cyclone is
forecast to reach the Pacific Northwest, bringing a period of unsettled
weather further inland as well as a general cool down to the region.  Rain
associated with the system is expected to reach the northern Rockies
Wednesday night/Thursday morning.  Some monsoonal moisture is forecast to
return near/west of the Four Corners region.

Current forecast of track and other information

Maps that relate the forecast to geography can be found by clicking  Here for Day 1 and Here for Day 2.

Here is a 60-hour animated forecast map that shows how the short-term forecast is expected to play out.

If it needs to be updated click here.

HAZARDS OUTLOOKS

Click here for the latest complete Day 3 -7 Hazards forecast which updates only on weekdays.  Once a week probably Monday or Tuesday I will update the images. I provided the link for readers to get daily updates on weekdays. Use your own judgment to decide if you need to update these images.  

Worldwide Tropical Forecast

(This graphic updates on Tuesdays) If it has not been updated, you can get the update by clicking here  This is a new approach and covers weeks 2 and 3 not weeks 1 and 2. It has more information but I am having trouble getting used to it. As usual, it comes with a discussion which is below

Outlook Discussion
Last Updated – 09/27/22
Valid – 10/05/22 – 10/18/22
Madden-Julian Oscillation (MJO) activity is increasing after a recent period of incoherent tropical convective activity. Tropical convection is coalescing into a wave 1-like pattern with enhanced(suppressed) convection over the Maritime Continent(Eastern Pacific) and modest eastward propagation of these features, especially the suppressed phase. Looking ahead, there is widespread agreement among dynamical model RMM-based forecasts for the high probability of an upcoming significant MJO event. The general consensus is that the RMM signal will emerge from the unit circle during the week-1 timeframe in phase 4 or 5 and amplify significantly while propagating slowly eastward during weeks 2-3.

Tropical cyclone (TC) activity has been high over the last week. A pair of TCs formed south of Japan (Noru, 9/22; Kulap, 9/25). Noru became a strong typhoon and is currently moving toward the Vietnam coast, while Kulap has stayed out to sea and is set to become an extratropical system in the coming days. TC Newton formed in the East Pacific on 9/21 and dissipated quickly without affecting land. TC Ashley formed in the southern Indian Ocean 9/26 but is not expected to have any impacts to land. In the Atlantic Basin, TC Hermine formed near the Cape Verde Islands on 9/23 and quickly dissipated. Later on 9/23, TC Ian formed in the Caribbean Sea, and is currently near Cuba as an intensifying hurricane. Ian is anticipated to come ashore along the eastern Gulf Coast in the coming days with the potential for heavy rain and high winds during the next few days. Please refer to the National Hurricane Center (NHC) for more information and the latest forecasts.

Looking ahead to week 2, heightened MJO activity and the La Niña base state when coupled with a westerly wind burst over the equatorial Indian Ocean depicted in multiple dynamical models provide favorable conditions for TC formation on either side of the equator for the Eastern Indian Ocean. Model guidance from the ECMWF and GEFS also indicate heightened probabilities of TC formation during the week-2 time period covering a broad area in Philippine Sea, the Eastern Pacific Basin and the Main Development Region (MDR) of the Atlantic Basin.

The precipitation outlook for the next two weeks is based on anticipated TC tracks, ongoing La Nina conditions, and consensus of GEFS, CFS, and ECMWF ensemble mean solutions. Suppressed (enhanced) rainfall continues near and to the west of the Date Line (over the Maritime Continent) due to ongoing La Nina conditions and anticipated MJO phase. Below-normal precipitation is anticipated for the western tropical Indian Ocean for both weeks 2 and 3.

For hazardous weather conditions in your area during the coming two-week period, please refer to your local NWS office, the Medium Range Hazards Forecast produced by the Weather Prediction Center, and the CPC Week-2 Hazards Outlook. Forecasts made over Africa are made in coordination with the International Desk at CPC.

Detailed Maps and Reports for the Western Atlantic and the Pacific Oceans

Below are three maps that summarize the situation for the Atlantic, Eastern and Central Pacific. Additional information can be accessed by clicking HE    RE

First the Atlantic

Click to view the forecast map and have access to additional information https://www.nhc .noaa.gov/gtwo.php?basin=  atlc&fdays=5

Then Eastern Pacific

Click to view the forecast map and have access to additional information https://www.nhc.noaa.gov/gtwo.php?basin=epac&fdays=5

Then Central Pacific

Click to view the forecast map and have access to additional information https://www.nhc.noaa.gov/gtwo.php?basin=cpac&fdays=5

And the Western Pacific

Click to view the forecast map and have access to additional information https://www.metoc.navy.mil/jtwc/jtwc.html

Some Intermediate-Term Outlooks

Links to “Outlook” maps and discussions for three time periods. Days 6 – 10, Days 8 – 14, and Weeks 3 and 4.  An outlook differs from a forecast based on how NOAA uses these terms in that an “outlook” presents information from deviation from normal and the likelihood of these deviations.

You have to click on the links because they do not update automatically and I do not want to have stale images in the article. But it is not difficult to click on a link and you get a large image plus a discussion. On Fridays in a separate article, we will show the images and provide a link in this article that article. But remember what you will see is the images as of Friday. But here you can get the current images simply by clicking on them. Then hit the return arrow at the upper left of your screen to return to the article. You will not find this information easily anywhere else.

The following is provided to help the reader relate the maps and the discussion that comes with the maps to how NWS will describe an area of the U.S.

https://i0.wp.com/www.wpc.ncep.noaa.gov/bndrys1.gif?w=1100&ssl=1

Days 6 – 10 Days 8 – 14 Weeks 3 and 4
https://www.cpc.ncep.noaa.gov/products/predictions/610day/ https://www.cpc.ncep.noaa.gov/products/predictions/814day/ https://www.cpc.ncep.noaa.gov/products/predictions/WK34/

Right now you can find these maps here (We show them every Friday there but you can click above and find them).

World Forecast for Day 6 (Currently Set for Day 6 but the reader can change that)

World Weather Forecast produced by the Australian Bureau of Meteorology. Unfortunately, I do not know how to extract the control panel and embed it into my report so that you could use the tool within my report. But if you visit it Click  Here and you will be able to use the tool to view temperature or many other things for THE WORLD. It can forecast out for a week. Pretty cool. Return to this report by using the “Back Arrow” usually found top left corner of your screen to the left of the URL Box. It may require hitting it a few times depending on how deep you are into the BOM tool. Below are the current worldwide precipitation and air pressure forecasts for six days out. They will not auto-update and right now are current for Day 6. If you want the forecast for a different day Click Here  I will try to update this map each day but you have the link so you can access the dashboard and get a wide variety of forecasts.I mostly rely on the reader to interpret world maps. For this map, areas of expected precipitation for the date and time shown are clearly shown. The number of High-Pressure systems shown is called the Wave Number. Maybe I will discuss WN someday. But it shows how many Rossby Waves there are around the World. Sometimes they are hard to count. Counting Low-Pressure systems should provide the same WN.  Rossby Waves are the way the temperature distribution of the Planet remains in balance. It is basically the science of fluid dynamics.  It can be very helpful in predicting the movement of weather patterns.  You can snip an area of interest and move it into MS Paint and enlarge it.

Month to Date Information

Month to date Temperature can be found at https://hprcc.unl.edu/products/maps/acis/MonthTDeptUS.png

Month to date Precipitation can be found at  https://hprcc.unl.edu/products/maps/acis/MonthPNormUS.png

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