Extreme Drought to Extreme Flood: Weather Whiplash Hits the Midwest

By: Dr. Jeff Masters , 2:42 PM GMT on April 19, 2013

It seems like just a few months ago barges were scraping bottom on the Mississippi River, and the Army Corps of Engineers was blowing up rocks on the bottom of the river to allow shipping to continue. Wait, it was just a few months ago--less than four months ago! Water levels on the Mississippi River at St. Louis bottomed out at -4.57' on January 1 of 2013, the 9th lowest water level since record keeping began in 1861, and just 1.6' above the all-time low-water record set in 1940 (after the great Dust Bowl drought of the 1930s.) But according to National Weather Service, the exceptional April rains and snows over the Upper Mississippi River watershed will drive the river by Tuesday to a height 45 feet higher than on January 1. The latest forecast calls for the river to hit 39.4' on Tuesday, which would be the 8th greatest flood in history at St. Louis, where flood records date back to 1861. Damaging major flooding is expected along a 250-mile stretch of the Mississippi from Quincy, Illinois to Thebes, Illinois next week. At the Alton, Illinois gauge, upstream from St.Louis, a flood height of 34' is expected on Tuesday. This would be the 6th highest flood in Alton since 1844, and damages to commercial property in the town of Alton occur at this water level. In addition, record flooding is expected on at least five rivers in Illinois and Michigan over the next few days. A crest 1.5' above the all-time record has already occurred on the Des Plaines River in Chicago. This river has invasive Asian Carp that could make their way into Lake Michigan if a 13-mile barrier along the river fails during an extreme flood. Fortunately, NPR in Michigan is reporting today that U.S. Army Corps of Engineers crews stationed along the 13-mile Asian carp barrier have seen no evidence of the fish breaching the structure, and it would have taken a flood much larger than today's record flood to breach the structure. A crest on the Grand River in Grand Rapids, Michigan nearly 4' above the previous record (period of record: at least 113 years) is expected this weekend. At this flood level, major flooding of residential areas is expected, though the flood wall protecting downtown Grand Rapids will keep the commercial center of the city from flooding.


Figure 1. The rains that fell in a 24-hour period ending at 7 am EDT Thursday, April 18, 2013 over Northern Illinois were the type of rains one would expect see fall only once every 40 years (yellow colors), according to METSTAT, Inc. (http://www.metstat.com.) METSTAT computed the recurrence interval statistics based on gauge-adjusted radar precipitation and frequency estimates from NOAA Atlas 14 Volume 2, published in 2004 (http://dipper.nws.noaa.gov/hdsc/pfds/.) METSTAT does not supply their precipitation recurrence interval forecasts or premium analysis products for free, but anyone can monitor the real-time analysis (observed) at: http://metstat.com/solutions/extreme-precipitation-index-analysis/

Damages from the April 2013 Midwest U.S. flood in Illinois, Michigan, and Missouri are likely to run into the hundreds of millions of dollars. Some of the impacts at the flood levels predicted include:

St. Louis, MO:
Major flooding begins. At this level the Choteau Island Levee, protecting 2400 acres, is overtopped. Also, Lemay Park just south of Lemay Ferry Road will begin flood

Cape Girardeau, MO:
Many homes in the Cape Girardeau area are affected and evacuations may be required. Over 100,000 acres is flooded. Numerous roads are closed.

Hannibal, MO:
The Sny Island and South Quincy levees are overtopped between River Mile 315.4 and 264.3, flooding 110,000 acres. The South River levee is overtopped between River Mile 320.5 and 312.1, flooding 10,000 acres.

Quincy, IL:
Missouri Highway 168 east of Palmyra near the BASF plant closes; Quincy Waterworks inundated.

Note that sandbagging efforts may be able to prevent some of these flooding impacts from occurring. Wunderground's weather historian Christopher C. Burt discusses the latest rainfall and flooding records from this week's epic storm in his latest post. He plans on an update Friday afternoon.


Figure 2. Water levels on the Mississippi River at St. Louis are predicted to crest at 39.5', near major flood stage, on Tuesday. This would be the 8th greatest flood in history at St. Louis. Records at the St. Louis gauge to back to 1861. Image credit: National Weather Service.


Figure 3. Water levels on the Mississippi River at St. Louis bottomed out at -4.57' on 01/01/2013, the 9th lowest water level since record keeping began in 1861, and just 1.6' above the all-time low-water record set in 1940, after the great Dust Bowl drought of the 1930s. Image credit: National Weather Service.

Flood-Drought-Flood Weather Whiplash
Residents along the Mississippi River have experienced a severe case of flood-drought-flood weather whiplash over the past two years. The Mississippi reached its highest level on record at New Madrid, Missouri on May 6, 2011, when the river crested at 48.35'. Flooding on the Mississippi and Missouri rivers that year cost an estimated $5 billion. The next year, after the great drought of 2012, the river had fallen by over 53' to an all time record low of -5.32' on August 30, 2012. Damage from the great drought is conservatively estimated at $35 billion. Next Tuesday, the river is expected to be at flood stage again in New Madrid, 40' higher than the August 2012 record low. Now, that is some serious weather whiplash. I'm often asked about the seemingly contradictory predictions from climate models that the world will see both worse floods and worse droughts due to global warming. Well, we have seen a classic example in the Midwest U.S. over the past two years of just how this kind of weather whiplash is possible. A warmer atmosphere is capable of bringing heavier downpours, since warmer air can hold more water vapor. We saw an example of this on Thursday morning, when an upper air balloon sounding over Lincoln, Illinois revealed near-record amounts of moisture for this time of year. The precipitable water--how much rain could fall if one condensed all the water vapor in a column above the ground into rain--was 1.62", just barely short of the Illinois April record for precipitable water of 1.64" set on April 20, 2000 (upper air records go back to 1948.) Thursday's powerful low pressure system was able to lift that copious moisture, cool it, and condense it into record rains. So how can you have worse droughts with more moisture in the air? Well, you still need a low pressure system to come along and wring that moisture out of the air to get rain. When natural fluctuations in jet stream patterns take storms away from a region, creating a drought, the extra water vapor in the air won't do you any good. There will be no mechanism to lift the moisture, condense it, and generate drought-busting rains. The drought that ensues will be more intense, since temperatures will be hotter and the soil will dry out more.

The new normal in the coming decades is going to be more and more extreme flood-drought-flood cycles like we are seeing now in the Midwest, and this sort of weather whiplash is going to be an increasingly severe pain in the neck for society. We'd better prepare for it, by building a more flood-resistant infrastructure and developing more drought-resistant grains, for example. And if we continue to allow heat-trapping gases like carbon dioxide continue to build up in the atmosphere at the current near-record pace, no amount of adaptation can prevent increasingly more violent cases of weather whiplash from being a serious threat to the global economy and the well-being of billions of people.


Video 1. One person was hospitalized after a sinkhole swallowed three cars in the South Deering neighborhood on the Southeast Side of Chicago on Thursday, April 18, 2013. Witnesses said the hole opened up around 5 a.m. at 9600 South Houston Avenue, quickly growing from about 20 feet to about 40 feet. First two cars slid in, then a third as the hole widened, witnesses said. A fourth vehicle was towed from the edge as it was about to fall inside. The sinkhole was due to heavy flooding that broke a water main built in 1915.

Related Science
A 2010 study by Duke University scientists suggests that global warming is the main cause of a significant intensification in the Bermuda High that in recent decades has more than doubled the frequency of abnormally wet or dry summer weather in the Southeast United States. Thus, the Southeast U.S. may see greater than its share of "Weather Whiplash"--extreme droughts followed by extreme floods--in coming decades. Joe Romm at climateporgress.org has a post discussing the paper, with links to examples of how the Southeast U.S. has seen both extreme droughts and extreme floods since 2005.


Jeff Masters

Underpass flooding (aerojad)
Belmont St. at the Metra train station.
Underpass flooding

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IN SOUTH FLORIDA..WHEN THE STREAMS,PONDS AND CREEKS OVERLOW..DO THE GATORS SWIM DOWN THE STREETS?
Member Since: August 6, 2011 Posts: 5 Comments: 56875
FLOOD ADVISORY
NATIONAL WEATHER SERVICE MIAMI FL
806 PM EDT SAT APR 20 2013

FLC021-210115-
/O.CON.KMFL.FA.Y.0013.000000T0000Z-130421T0115Z/
/00000.N.ER.000000T0000Z.000000T0000Z.000000T0000 Z.OO/
COLLIER FL-
806 PM EDT SAT APR 20 2013

...THE URBAN FLOOD ADVISORY REMAINS IN EFFECT UNTIL 915 PM EDT FOR
CENTRAL COLLIER COUNTY...

AT 757 PM EDT...NATIONAL WEATHER SERVICE DOPPLER RADAR INDICATED 2
TO 4 INCHES OF RAIN HAD FALLEN OVER ORANGE TREE AND GOLDEN GATE
ESTATES. THE STORM REMAINS NEARLY STATIONARY. ADDITIONAL RAINFALL
AMOUNTS OF 1 TO 2 INCHES ARE POSSIBLE.

HEAVY RAINFALL WILL CAUSE PONDING OF WATER IN URBAN AREAS...
HIGHWAYS...STREETS AND UNDERPASSES AS WELL AS OTHER POOR DRAINAGE
AREAS AND LOW LYING SPOTS. RUNOFF WILL ALSO CAUSE ELEVATED LEVELS ON
SMALL CREEKS AND STREAMS.

EXCESSIVE RUNOFF FROM HEAVY RAINFALL WILL CAUSE ELEVATED LEVELS ON
SMALL CREEKS AND STREAMS...AND PONDING OF WATER ON COUNTRY ROADS AND
FARMLAND ALONG THE BANKS OF CREEKS AND STREAMS.

LAT...LON 2632 8167 2632 8166 2637 8167 2637 8144
2616 8144 2617 8167 2632 8169

$$

AK
Member Since: August 6, 2011 Posts: 5 Comments: 56875
Pre-frontal showers and isolated thunderstorms have developed to the west of Hawaii ahead of an approaching front. This will bring some potential heavy showers to Kauai and Niihau by tomorrow. Thus, flash flood watch will be in effect for the Kauai County starting tomorrow morning through Tuesday morning. The watch may extend to Oahu later on as that island will likely receive some heavy rain as well.

Member Since: Posts: Comments:


SoCal Fire
Member Since: February 29, 2012 Posts: 0 Comments: 7340
BAD STORMS IN SOUTH FLORIDA..STAY SAFE FOLKS.....SPECIAL WEATHER STATEMENT
NATIONAL WEATHER SERVICE MIAMI FL
802 PM EDT SAT APR 20 2013

FLZ070-210030-
INLAND COLLIER COUNTY FL
802 PM EDT SAT APR 20 2013

...A SIGNIFICANT WEATHER ADVISORY IS IN EFFECT FOR NORTHERN COLLIER
COUNTY...FOR FREQUENT TO EXCESSIVE LIGHTNING...GUSTY WINDS FROM 45 TO
55 MPH...UP TO NICKEL-SIZED HAIL...

* UNTIL 830 PM EDT

* AT 800 PM EDT...NATIONAL WEATHER SERVICE METEOROLOGISTS DETECTED A
STRONG THUNDERSTORM NEAR BIG CORKSCREW ISLAND...AND MOVING NORTH AT
10 MPH.

* THE STORM WILL AFFECT...
IMMOKALEE...
CORKSCREW SWAMP SANCTUARY...
AND SURROUNDING COMMUNITIES.

FREQUENT TO EXCESSIVE LIGHTNING...GUSTY WINDS FROM 45 TO 55 MPH...UP
TO NICKEL SIZED HAIL...TORRENTIAL DOWNPOURS...OR A COMBINATION OF
THESE ARE POSSIBLE. LIGHTNING IS THE NUMBER ONE WEATHER RELATED
KILLER IN FLORIDA. TREES AND OPEN SHELTERS OFFER NO PROTECTION.
THESE WINDS CAN DOWN SMALL TREE LIMBS AND BRANCHES...AND BLOW AROUND
UNSECURED SMALL OBJECTS. SEEK SHELTER IN A SAFE BUILDING UNTIL THE
STORM PASSES.
Member Since: August 6, 2011 Posts: 5 Comments: 56875
Member Since: August 6, 2011 Posts: 5 Comments: 56875
tomorrows outlook...
Member Since: August 6, 2011 Posts: 5 Comments: 56875
well ft Meyers will get some good rains...
Member Since: August 6, 2011 Posts: 5 Comments: 56875
SHORT TERM FORECAST
NATIONAL WEATHER SERVICE TAMPA BAY AREA - RUSKIN FL
739 PM EDT SAT APR 20 2013

FLZ042-043-048-049-060-062-065-GMZ850-856-210045-
CITRUS-SUMTER-HERNANDO-PASCO-SARASOTA-CHARLOTTE-L EE-
TARPON SPRINGS TO SUWANNEE RIVER OUT 20 NM-
BONITA BEACH TO ENGLEWOOD OUT 20 NM-
739 PM EDT SAT APR 20 2013

.NOW...
A THUNDERSTORM WAS BUILDING OVER LEHIGH ACRES WITH HEAVY
RAIN...GUSTY WINDS AND DANGEROUS LIGHTNING. OTHER SCATTERED
SHOWERS OVER THE GULF WILL MOVE INTO AREAS AROUND CHARLOTTE HARBOR
AND INTO THE NATURE COAST AREAS FROM SPRING HILL TO HOMOSASSA AND
INLAND TO THE VILLAGES.

$$

TD
Member Since: August 6, 2011 Posts: 5 Comments: 56875
this is the 2nd or 3rd front that has washed over florida and every time it rains to the north and south of tampa bay and not a drop here..shields down please Tampa lol
Member Since: August 6, 2011 Posts: 5 Comments: 56875

back to freezing... (come on!)
Member Since: April 23, 2011 Posts: 104 Comments: 14876
Quoting amatuermet:
Hey everyone,

I have recently finished my forecast and came of with the numbers:

16-24 Named Storms

8-12 Hurricanes

4-6 Major Hurricanes


welcome to WU!

I wrote you down..thanks
you're the 104th
Member Since: April 23, 2011 Posts: 104 Comments: 14876
Quoting VR46L:


It would appear the Tampa Shield is more than a myth ... Last week I just could not believe it , was less hopeful for today .. I just feel for the folks in that area as they really need rain


Actually it is more of a social phenomenon than anything else. These unusual stubborn tendencies in meteorology can be observed in many other regions, whether it be drought or flood, extreme heat or extreme cold.

It's just that we have a lot of users in the Tampa Bay area, and Central Florida has very sandy soil with a limestone base below this sandy soil. Therefore, it dries out very quickly without frequent heavy rains, and so its painful for many to experience a lack of rain repeatedly.

However, you will be able to observe the strange phenomenon of such a stubborn pattern in other regions. For example, the tendency of rain to continue to not materialize over a given region despite the models repeatedly insisting on it happening. It's not just a model issue, as I mentioned earlier, the parameters did turn out like the models predicted, yet rain still did not materialize.

I don't know how to explain this. However, I've also seen it happen in the opposite way, repeated active rain events even when it seems illogical that its happening, I've seen during really wet periods in Central Florida in the summer where the forecast will call for a drop in rain chances to say 20%, but despite this, the atmosphere manages to erupt with numerous thunderstorms to a degree that would seem contrary to what is possible.

Essentially what I'm trying to say, is that there is a strange phenomenon where actual weather results repeatedly seem to almost defy meteorology in terms of acceptable parameters for a given outcome.


Not only is it hard to explain this odd occurrence, but its also hard to prove, given the obvious.

Member Since: August 21, 2008 Posts: 0 Comments: 9953
and more on the way out in the gulf..........FLOOD ADVISORY
NATIONAL WEATHER SERVICE MIAMI FL
719 PM EDT SAT APR 20 2013

FLC021-210115-
/O.NEW.KMFL.FA.Y.0013.130420T2319Z-130421T0115Z/
/00000.N.ER.000000T0000Z.000000T0000Z.000000T0000 Z.OO/
719 PM EDT SAT APR 20 2013

THE NATIONAL WEATHER SERVICE IN MIAMI HAS ISSUED AN

* URBAN FLOOD ADVISORY FOR...
CENTRAL COLLIER COUNTY IN SOUTHWEST FLORIDA...

* UNTIL 915 PM EDT

* AT 714 PM EDT...NATIONAL WEATHER SERVICE DOPPLER RADAR INDICATED A
THUNDERSTORM THAT WAS NEARLY STATIONARY OVER ORANGE TREE AND GOLDEN
GATE ESTATES. RADAR ESTIMATES 1 TO 3 INCHES OF RAIN HAS FALLEN IN
THE LAST 30 MINUTES.

ADDITIONAL RAINFALL AMOUNTS OF 1 TO 3 INCHES WITH LOCALLY HIGHER
AMOUNTS ARE POSSIBLE IN THE ADVISED AREA.

HEAVY RAINFALL WILL CAUSE PONDING OF WATER IN URBAN AREAS, HIGHWAYS,
STREETS AND UNDERPASSES AS WELL AS OTHER POOR DRAINAGE AREAS AND LOW
LYING SPOTS. RUNOFF WILL ALSO CAUSE ELEVATED WATERS LEVELS IN CANALS
AND DITCHES.

LAT...LON 2632 8167 2632 8166 2637 8167 2637 8144
2616 8144 2617 8167 2632 8169

$$

AK
Member Since: August 6, 2011 Posts: 5 Comments: 56875
Member Since: August 6, 2011 Posts: 5 Comments: 56875
Member Since: July 15, 2006 Posts: 195 Comments: 61084
rain to the north and south of me and Not a DROP for me lol..
Member Since: August 6, 2011 Posts: 5 Comments: 56875
Hey everyone,

I have recently finished my forecast and came of with the numbers:

16-24 Named Storms

8-12 Hurricanes

4-6 Major Hurricanes
Member Since: Posts: Comments:
Member Since: August 6, 2011 Posts: 5 Comments: 56875
south Florida..another BIG blob of rain coming in soon..
Member Since: August 6, 2011 Posts: 5 Comments: 56875


Member Since: Posts: Comments:
Quoting TropicalAnalystwx13:
Here's my preliminary temperature forecast for the USA during the month of May:


:(
Winter just doesn't want to go away in the Great Lakes and Upper Plains.
Member Since: March 16, 2012 Posts: 127 Comments: 7984
Member Since: Posts: Comments:
Quoting yoboi:



you think we will have an active atlantic season?????????




i dont no
Member Since: May 21, 2006 Posts: 5100 Comments: 117339
Quoting TropicalAnalystwx13:
Here's my preliminary temperature forecast for the USA during the month of May:



Mild works for me....
Member Since: February 29, 2012 Posts: 0 Comments: 7340
Positive Atlantic tripole:

Member Since: Posts: Comments:
611. yoboi
Quoting Tazmanian:



good



you think we will have an active atlantic season?????????
Member Since: August 25, 2010 Posts: 9 Comments: 3415
Here's my preliminary temperature forecast for the USA during the month of May:

Member Since: July 6, 2010 Posts: 113 Comments: 34842
Quoting yoboi:


long time no talk how ya doin????



good
Member Since: May 21, 2006 Posts: 5100 Comments: 117339
608. yoboi
Quoting Tazmanian:



LOL there is no EL NINO


long time no talk how ya doin????
Member Since: August 25, 2010 Posts: 9 Comments: 3415


Member Since: Posts: Comments:
606. etxwx
Did someone say they were bored? Let the itching begin!
Actually this is a pretty interesting science story and a possible environmentally friendly solution to bed bugs.

Bed bugs thwarted by kidney bean leaves, study shows
By AMINA KHAN | Los Angeles Times via McClatchy

Excerpt: LOS ANGELES — Bed bugs have re-emerged as an urban blight in the past several years, forcing people out of homes, resisting chemical pesticides and evading other removal tactics. But researchers are building bug-catchers inspired by an age-old folk remedy to this "ancient scourge": kidney bean leaves.

The leaves sport tiny, sharp-hooked hairs called trichomes across their surface. These microscopic hooks, 10 micrometers in diameter and 50 to 100 micrometers high, jab into the insects' bodies, trapping them before they get very far. Even those that break free are often trapped again a few steps later.

Read about the whole experiment including an attempt to make synthetic leaves here.

You can stop itching now...
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Member Since: Posts: Comments:
Member Since: September 10, 2007 Posts: 0 Comments: 12427
GFS now..........
Member Since: August 6, 2011 Posts: 5 Comments: 56875
THIS HAZARDOUS WEATHER OUTLOOK IS FOR NORTHEAST FLORIDA...SOUTHEAST
GEORGIA AND THE ADJACENT COASTAL WATERS.

.DAY ONE...THIS AFTERNOON AND TONIGHT...

WINDS BEGIN TO INCREASE LATE TONIGHT AS LOCAL NOR`EASTER CONDITIONS
DEVELOP AND SMALL CRAFT ADVISORIES WILL GO INTO EFFECT.

.DAYS TWO THROUGH SEVEN...SUNDAY THROUGH FRIDAY...

WINDS WILL INCREASE FURTHER SUNDAY INTO MONDAY AS HIGH PRESSURE
STRENGTHENS NORTH OF THE AREA AND A TROUGH OF LOW PRESSURE DEVELOPS
EAST OF THE FLORIDA PENINSULA. WIND ADVISORIES MAY BE NEEDED SUNDAY
AND POSSIBLY AGAIN MONDAY FOR COASTAL AREAS...WITH SMALL CRAFT
ADVISORY CONDITIONS OVER THE ADJACENT COASTAL WATERS.

INCREASED AND PERSISTENT ONSHORE FLOW WILL CREATE DANGEROUS MARINE
CONDITIONS DURING THE UPCOMING WEEK...INCLUDING DANGEROUS RIP
CURRENTS...ELEVATED BREAKERS...AND THE POSSIBILITY OF MINOR TIDAL
FLOODING AROUND THE TIMES OF HIGH TIDE BY MIDWEEK.

.SPOTTER INFORMATION STATEMENT...

SPOTTER ACTIVATION IS NOT REQUESTED AT THIS TIME.

FOR ADDITIONAL INFORMATION...VISIT THE NATIONAL WEATHER SERVICE
IN JACKSONVILLE WEBSITE ON THE INTERNET AT WEATHER.GOV/JAX.
Member Since: August 6, 2011 Posts: 5 Comments: 56875
601. LargoFl
10:26 PM GMT on April 20, 2013
Member Since: August 6, 2011 Posts: 5 Comments: 56875
600. TropicalAnalystwx13
10:26 PM GMT on April 20, 2013
One of the best surface analysis maps I know of. Click to zoom, and then click to zoom.

Member Since: July 6, 2010 Posts: 113 Comments: 34842
599. LargoFl
10:24 PM GMT on April 20, 2013
I just do not understand,2nd front and no rain again....
Member Since: August 6, 2011 Posts: 5 Comments: 56875
598. beell
10:24 PM GMT on April 20, 2013
Quoting Jedkins01:
Despite several systems bringing favorable conditions for showers and thunderstorms to West Central Florida the past few weeks, the area manages to stay somehow nearly rain free, it is very puzzling to me. It's one thing to lack in rain because there isn't any conditions favorable to produce the rain, its another when everything is in place for at least decent shower and thunderstorm coverage, and yet still, nothing!

Right now, one would think that a potent upper trough, jet energy, and large amounts of deep layer moisture with a PWAT of 1.8 inches would spark plenty of showers and thunderstorms, but no, not in this case:



At this point, people are probably starting to get angry with forecasters in the Tampa Bay area for forecasting beneficial rain repeatedly that never materializes. However, you can't get mad at the forecasters once you understand that the atmosphere has evolved just the way they expected by the models, and naturally any meteorologist would expect rain in such a situation, yet still, puzzling as it may be, no rain, even though the parameters are in the same range as expected by the models, yet the models have shown good precip coverage but nothing is happening.





We don't get much rain behind a front here, either.

Not seeing much of a "potent upper trough" over central Florida. You got decent mid-level flow from the SW and that's enough for some light post-frontal stratiform rain. The front is south of Lake O.
Member Since: September 11, 2007 Posts: 158 Comments: 18960
597. LargoFl
10:23 PM GMT on April 20, 2013
COASTAL MIAMI DADE-
615 PM EDT SAT APR 20 2013

.NOW...
THE LATEST RADAR LOOP SHOWED THE STRONG STORMS THAT MOVED THROUGH
BROWARD AND NORTHEAST MIAMI-DADE COUNTIES NOW OFF THE COAST AND
CONTINUING EASTWARD. MODERATE TO HEAVY SHOWERS WILL REMAIN
POSSIBLE ALONG THE IMMEDIATE COAST FOR THE UPCOMING 30 MINUTES TO
AN HOUR...MAINLY FROM SOUTHEAST BROWARD TO KEY BISCAYNE. RAINFALL
ACCUMULATIONS HAVE ALREADY REACHED THE 2 TO 4 INCH RANGE OVER
PORTIONS OF THE EAST COAST AND AN ADDITIONAL INCH WILL REMAIN
POSSIBLE WITHIN THE UPCOMING 30 MINUTES OVER MIAMI BEACH AND KEY
BISCAYNE BEFORE MOVING OFF THE COAST. OVER THE WATERS...MARINERS
CAN EXPECT TO CONTINUE TO SEE STRONG THUNDERSTORMS WITH HEAVY
RAINFALL AND GUSTY WINDS THROUGH 7 PM.

$$
Member Since: August 6, 2011 Posts: 5 Comments: 56875
596. LargoFl
10:20 PM GMT on April 20, 2013
Member Since: August 6, 2011 Posts: 5 Comments: 56875
595. Tazmanian
10:19 PM GMT on April 20, 2013
Quoting yoboi:



what does el nino look like taz>???



LOL there is no EL NINO
Member Since: May 21, 2006 Posts: 5100 Comments: 117339
594. KEEPEROFTHEGATE
10:17 PM GMT on April 20, 2013
Toronto Pearson Int'l Airport
Date: 6:00 PM EDT Saturday 20 April 2013Condition
:Mostly Cloudy
Pressure:30.2 inches
Tendency:rising
Visibility:15 miles
Temperature:35.6°F
Dewpoint:18.5°F
Humidity:49%
Wind:WNW 21 gust 30 mph


normal is 55 for this time of year we are 19.4 degrees below normal right now
Member Since: July 15, 2006 Posts: 195 Comments: 61084
593. KEEPEROFTHEGATE
10:14 PM GMT on April 20, 2013
Member Since: July 15, 2006 Posts: 195 Comments: 61084
592. GeoffreyWPB
10:10 PM GMT on April 20, 2013
Miami NWS Disco

THE CURRENT 500 MB PATTERN SHOWS A TROUGH OF LOW PRESSURE OVER THE
EASTERN AND CENTRAL US AND A STRONG BLOCKING RIDGE OF HIGH PRESSURE
OVER THE WESTERN ATLANTIC. AS THE HIGH CONTINUES TO MOVE FURTHER
EAST COOLER 500 MB TEMPERATURES WILL SPREAD OVER SOUTH FLORIDA ON
SUNDAY. THIS IS EXPECTED TO INCREASE THE POTENTIAL FOR STRONG OR
EVEN SEVERE STORMS ON SUNDAY IF HEATING IS FAVORABLE.
Member Since: September 10, 2007 Posts: 0 Comments: 12427
591. BaltimoreBrian
10:08 PM GMT on April 20, 2013
Quoting Jedkins01:
Despite several systems bringing favorable conditions for showers and thunderstorms to West Central Florida the past few weeks, the area manages to stay somehow nearly rain free, it is very puzzling to me. It's one thing to lack in rain because there isn't any conditions favorable to produce the rain, its another when everything is in place for at least decent shower and thunderstorm coverage, and yet still, nothing!

Right now, one would think that a potent upper trough, jet energy, and large amounts of deep layer moisture with a PWAT of 1.8 inches would spark plenty of showers and thunderstorms, but no, not in this case:



At this point, people are probably starting to get angry with forecasters in the Tampa Bay area for forecasting beneficial rain repeatedly that never materializes. However, you can't get mad at the forecasters once you understand that the atmosphere has evolved just the way they expected by the models, and naturally any meteorologist would expect rain in such a situation, yet still, puzzling as it may be, no rain, even though the parameters are in the same range as expected by the models, yet the models have shown good precip coverage but nothing is happening.





Our knowledge is incomplete. People like you will discover more about what factors are involved in convection initiation and their parameters.
Member Since: August 9, 2011 Posts: 27 Comments: 12253
590. KEEPEROFTHEGATE
10:07 PM GMT on April 20, 2013
about 45 mins by car from me

we got nothing a brief heavy shower and some gusty winds lasted maybe 10 minutes if that no thunder or lightening even seen one flash to the nw but it was far away

storms were trackin ene too my nw so they were moving away from us instead of heading towards us
Member Since: July 15, 2006 Posts: 195 Comments: 61084
589. PedleyCA
9:58 PM GMT on April 20, 2013
Quoting KEEPEROFTHEGATE:


ya from 70's 2 days ago to near freezing today and cool for the rest of the week as well


How far was that tornado from your area?
Member Since: February 29, 2012 Posts: 0 Comments: 7340
588. KEEPEROFTHEGATE
9:57 PM GMT on April 20, 2013
Quoting PedleyCA:


I see your weather is back to square one.


ya from 70's 2 days ago to near freezing today and cool for the rest of the week as well
Member Since: July 15, 2006 Posts: 195 Comments: 61084
587. KEEPEROFTHEGATE
9:55 PM GMT on April 20, 2013
AWCN11 CWTO 201925
Updated weather summary 20 April 2013.

------------------------------------------------- ------------
==weather event discussion==

..First tornado of the season in Ontario confirmed..

Note: summary updated to increase tornado path to 10 km.

At approximately 5:45 PM EDT on Thursday, April 18, a strong line of
thunderstorms moved through the Shelburne area to the northwest of
Toronto. Based on a damage survey by Environment Canada personnel,
one of these thunderstorms produced a brief enhanced Fujita (ef) 1
tornado approximately 6 kilometres to the northwest of Shelburne. An
ef-1 tornado has peak winds between 135 and 175 kilometres per hour.
The Key damage noted at this scene was a barn with its roof and two
walls removed with some pieces of the barn firmly embedded into the
ground at a distance of 50 to 100 metres from the original location.
The total length of the damage path was 10 km with a width of
75 metres. Investigations are continuing in this area that may
Result in the length and width of the damage track changing or of
The possibility of other tornadoes. This statement will be updated
As new information becomes available.

This is the first tornado of the season, not only in Ontario but in
all of Canada. The summer severe weather season normally begins in
late April and ends in early October. Ontario sees an average of 12
tornadoes each year. This tornado also represents the first tornado
in Canada to be rated using the enhanced Fujita (ef) scale as opposed
to the original Fujita scale. The National Weather Service adopted
the ef scale in 2007 and Environment Canada has monitored its use
since that time and has decided to also adopt this scale beginning
this year. The types of damage produced by tornadoes on either the
enhanced Fujita scale or the original Fujita scale are similar.
However, the wind speeds of the various categories have been adjusted
based on the best available knowledge concerning the winds required
to damage structures, vehicles and trees.

This weather summary contains preliminary information and may not
constitute an official or final report.

END/OSPC
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Dr. Masters (r) co-founded wunderground in 1995. He flew with the NOAA Hurricane Hunters 1986-1990. Co-blogging with him: Bob Henson, @bhensonweather

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Afternoon clouds over Southwest Puerto Rico
Storm clouds gathering over Half Dome
Sierra snow
snowman at Yosemite Falls