Red River rising: 18th consecutive year of flooding--why?

By: Dr. Jeff Masters , 3:08 PM GMT on March 19, 2010

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The Red River at Fargo, North Dakota continues to rise, with a peak expected Sunday at the 4th highest flood level observed in the past century. "Major" flood level is 30 feet, which the river surpassed on Wednesday, and the river is expected to crest near 38 feet on Sunday, just 2.8 feet below the record set last year. Flood stage is eighteen feet, and the Red River has now reached flood stage at Fargo for eighteen consecutive years, according to the U.S. Army Corps of Engineers. Prior to this remarkable stretch of flooding (which began in 1993), the river flooded in just 29 of 90 years. This year's flood is rated as somewhere between a 50-year and 100-year flood. Last year's record flood was a 100-year flood. The U.S. Army Corps of Engineers lists the 10-year flood level for the Red River at Fargo to be 10,300 cubic feet per second. A 10-year flood, historically, has a 10% chance of occurring in a given year. In the last twenty years, the Red River has had eight 10-year floods--one every 2.5 years, on average. This year is the fourth year out of the past five with a 10-year flood. Clearly, flooding has increased significantly along the Red River over the past twenty years.


Figure 1. Current and forecast flood stage for the Red River of the North at Fargo, ND. You can access images like these using our wundermap for Fargo with the "USGS River" layer turned on. Click on the icon for USGS station 05054000, then hit the "click for graph" link.

Reasons for flooding: landform factors
According the U.S. Geological Survey, the unique landform characteristics of the Red River Valley make it highly susceptible to flooding. These factors include:

1) A relatively shallow and meandering river channel--a shallow channel holds less water and the meandering can cause flow to slow down as the channel makes its turns, causing over-bank flooding.

2) A gentle slope (averaging 0.5 to 1.5 feet per mile) that inhibits channel flow and encourages overland flooding or water "ponding" (especially on even, saturated ground) in the basin.

3) The northerly direction of flow--flow in the Red River travels from south (upstream) to north (downstream). The direction of flow becomes a critical factor in the spring when the southern (upstream) part of the Red River has thawed and the northern (downstream) part of the channel is still frozen. As water moves north toward the still frozen river channel, ice jams and substantial backwater flow and flooding can occur.


Figure 2. Peak flow of the Red River at Fargo, North Dakota through time. The two largest flow rates occurred last year (2009), and in 1997. The projected crest for Sunday (red circle) would be fourth greatest flood since reliable records began in 1901. Image credit: U.S. Geological Survey.

Reasons for this year's flood: highly unfavorable weather conditions
The USGS also cites five weather factors that can act to enhance flooding along the Red River. All five of these factors occurred to a significant degree this year:

1) Above-normal amounts of precipitation in the fall of the year that produce high levels of soil moisture, particularly in flat surface areas, in the basin. North Dakota had its 22nd wettest fall in the 115-year record in 2009.

2) Freezing of saturated ground in late fall or early winter, before significant snowfall occurs, that produces a hard, deep frost that limits infiltration of runoff during snowmelt. Fargo had a November that was much warmer than average, followed by a sudden plunge to below-zero temperatures by the second week of December. This froze the saturated ground to a great depth.

3) Above-normal winter snowfall in the basin. North Dakota had a top 15% winter for precipitation, with the period December 2009 - February 2010 ranking 15th wettest in the past 115 years.

4) Above-normal precipitation during snowmelt. Precipitation for March 1 - 18 has been 1.41", compared to the average of 0.61".

5) Above-normal temperatures during snowmelt. High temperatures in Fargo have averaged 6°F warmer than normal for March 1 - 18.

Urbanization increases flooding
Urbanization has had a major impact on increasing flooding not only along the Red River, but in every river basin in the U.S. Many cities and developed areas are located in flood plains next to major rivers and their tributaries. Highways, streets, parking lots, sidewalks, and buildings now cover large areas of the ground that used to absorb excess rain water and slow the rate at which run-off from precipitation and melting snow reached rivers. By developing large portions of our flood plains, run-off now reaches rivers more quickly, generating higher floods.

Building levees and flood defenses increases flood peaks
Defending ourselves against floods has made floods worse. Every time a new levee is built, or an old floodwall raised in height to prevent overtopping, more and more water is forced into the river bed, which raises the height of the flood. Flood waters that used to be able to spread out over their natural flood plains are now forbidden from spilling out over newly developed land in flood plains. For example, proposed improvements to the flood defense system in Fargo could cause a 4 - 10 inch rise in floods immediately downstream from the city, according to the Army Corps of Engineers.

Precipitation is increasing
As the climate warms, evaporation of moisture from the oceans increases, resulting in more water vapor in the air. According to the 2007 IPCC report, water vapor in the global atmosphere has increased by about 5% over the 20th century, and 4% since 1970. Satellite measurements (Trenberth et al., 2005) have shown a 1.3% per decade increase in water vapor over the global oceans since 1988. Santer et al. (2007) used a climate model to study the relative contribution of natural and human-caused effects on increasing water vapor, and concluded that this increase was "primarily due to human-caused increases in greenhouse gases". This was also the conclusion of Willet et al. (2007). This increase in water vapor has very likely led to an increase in global precipitation. For instance, over the U.S., where we have very good precipitation records, annual average precipitation has increased 7% over the past century (Groisman et al., 2004). Precipitation over the Red River drainage basin increased by about 10 - 20% during the 20th Century (Figure 3.) The same study also found a 14% increase in heavy (top 5%) and 20% increase in very heavy (top 1%) precipitation events over the U.S. in the past century. These are the type of events most likely to cause flooding. Kunkel et al. (2003) also found an increase in heavy precipitation events over the U.S. in recent decades, but noted that heavy precipitation events were nearly as frequent at the end of the 19th century and beginning of the 20th century, though the data is not as reliable back then.


Figure 3. Change in precipitation over the U.S. between 1900 - 2000, from the U.S. Cooperative network. Precipitation in the Red River drainage area increased by 10 - 20% over the 20th century. Image credit: Contemporary Changes of the Hydrological Cycle over the Contiguous United States: Trends (Groisman et al., 2002).

The future of flooding
As the population continues to expand, development in flood plains and construction of new levees and flood protection systems will continue to push floods to higher heights. With global warming expected to continue and drive ever higher precipitation amounts--falling preferentially in heavy precipitation events--it is highly probable that flooding in the Red River Valley--and over most of the northern 2/3 of the U.S. where precipitation increases are likely--will see higher and more frequent floods. With these higher and more frequent floods comes the increased risk of multi-billion dollar disasters, when a record flood event overwhelms flood defenses and inundates huge areas of developed flood plains. Obviously, we need to make smart decisions to limit development in flood plains to reduce the cost and suffering of these future flooding disasters.

References
Kunkel, K. E., D. R. Easterling, K. Redmond, and K. Hubbard, 2003, "Temporal variations of extreme precipitation events in the United States: 1895.2000", Geophys. Res. Lett., 30(17), 1900, doi:10.1029/2003GL018052.

Groisman, P.Y., R.W. Knight, T.R. Karl, D.R. Easterling, B. Sun, and J.H. Lawrimore, 2004, "Contemporary Changes of the Hydrological Cycle over the Contiguous United States: Trends Derived from In Situ Observations," J. Hydrometeor., 5, 64.85.

Milly, P.C.D., R.T. Wetherald, K.A. Dunne, and T.L.Delworth, Increasing risk of great floods in a changing climate", Nature 415, 514-517 (31 January 2002) | doi:10.1038/415514a.

Santer, B.D., C. Mears, F. J. Wentz, K. E. Taylor, P. J. Gleckler, T. M. L. Wigley, T. P. Barnett, J. S. Boyle, W. Brüggemann, N. P. Gillett, S. A. Klein, G. A. Meehl, T. Nozawa, D. W. Pierce, P. A. Stott, W. M. Washington, and M. F. Wehner, 2007, "Identification of human-induced changes in atmospheric moisture content", PNAS 2007 104: 15248-15253.

Trenberth, K.E., J. Fasullo, and L. Smith, 2005: "Trends and variability in column-integrated atmospheric water vapor", Climate Dynamics 24, 741-758.

Willett, K.M., N.P. Gillett, P.D. Jones, and P.W. Thorne, 2007, "Attribution of observed surface humidity changes to human influence", Nature 449, 710-712 (11 October 2007) | doi:10.1038/nature06207.

Links
A good way to track the flooding event is to use our wundermap for the Red River with the USGS River layer turned on.

The Fargo Flood webpage of North Dakota State University, Fargo, has some excellent links.

I'll have a new post on Monday or Tuesday.

Jeff Masters

Red River Flood 2006 (mw25)
The water level of the Red River when I took this photo was 47.2 feet, 19.2 feet above flood stage and the 6th highest level in Grand Forks' history. The river is expected to crest at 47.4 feet on Wednesday morning. Luckily, no homes have been lost in the Grand Forks area as of yet due to the flooding.
Red River Flood 2006
Fargo Flood 2009 - Elm & 15th Ave. N. (tliebenow)
Picture says it all. Clay dike built to contain the Red River in North Fargo.
Fargo Flood 2009 - Elm & 15th Ave. N.

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1161. JRRP
5:12 AM GMT on March 23, 2010
Quoting Levi32:
Wrong blog JRRP. Lol.

lol... jejeje
i´m a bit late

Member Since: August 16, 2007 Posts: 0 Comments: 5337
1160. Levi32
4:47 AM GMT on March 23, 2010
Wrong blog JRRP. Lol.
Member Since: November 24, 2005 Posts: 635 Comments: 26547
1159. JRRP
4:42 AM GMT on March 23, 2010


Member Since: August 16, 2007 Posts: 0 Comments: 5337
1158. PcolaDan
1:09 AM GMT on March 23, 2010
Quoting Skyepony:
I scored shuttle launch tickets from the turn basin (next to the VAB & a little closer than media:))


That's just awesome!!!!!!
btw new blog since about 4 ;)
Member Since: August 22, 2008 Posts: 12 Comments: 6010
1157. Skyepony (Mod)
12:44 AM GMT on March 23, 2010
I scored shuttle launch tickets from the turn basin (next to the VAB & a little closer than media:))
Member Since: August 10, 2005 Posts: 161 Comments: 37346
1156. GeoffreyWPB
12:32 AM GMT on March 23, 2010
A little trivia...the name Arlene (same spelling) is the most used name in Hurricane history. In 2011, she will extend her streak to eight times.
Member Since: September 10, 2007 Posts: 0 Comments: 10975
1155. GeoffreyWPB
12:01 AM GMT on March 23, 2010
Olbermann is back on Countdown. First time after his father's passing. Should be an interesting show.
Member Since: September 10, 2007 Posts: 0 Comments: 10975
1154. Skyepony (Mod)
11:08 PM GMT on March 22, 2010
Quoting Jeff9641:
Another amazing fact is that our water table in C FL is at summertime levels and our rainy season starts the end of May. With TS and hurricanes affecting FLorida this year we should top our yearly rainfall record in Orlando at 69.78" set back in 1969.


Climo tells us better chance then not that El Nino brings the wet, cool winter..extra growth & hard freeze. Something about coming out, usually the spring & summer after el Nino the rains many years like this one, have quit & parts of FL burn down. The most memorable for me was '98 & '83.. Not saying it's a sure thing but certainly not ready to make any bets that rain records fall in ECFL this year.
Member Since: August 10, 2005 Posts: 161 Comments: 37346
1153. PcolaDan
10:52 PM GMT on March 22, 2010
Iceland volcano could have world consequences

An interesting read.
Member Since: August 22, 2008 Posts: 12 Comments: 6010
1152. GeoffreyWPB
9:37 PM GMT on March 22, 2010
Hurricane Jeanne

Member Since: September 10, 2007 Posts: 0 Comments: 10975
1151. GeoffreyWPB
9:22 PM GMT on March 22, 2010
Quoting StormChaser81:


It's because Frances was a more powerful storm and the second storm in two weeks to make landfall in Florida.

Our local media covered both storms expertly. Frances struck first as a Cat. 2 on Sept. 4 and Jeanne on Sept. 26 as a Cat. 3. These two storms were major pains as we lost power for a total of more than three weeks. Plus, I was out of work for 17 consecutive days, including the remnants of Ivan.
Member Since: September 10, 2007 Posts: 0 Comments: 10975
1150. AllStar17
9:02 PM GMT on March 22, 2010
Quoting Patrap:


Thats some cool Graphic for sure..

Those could sell..


Thanks! I used Microsoft PowerPoint 2007.
Member Since: June 29, 2009 Posts: 13 Comments: 5300
1149. StormChaser81
8:51 PM GMT on March 22, 2010
Quoting troy1993:
Hey Levi 32..What were the differences between Hurricane Frances and Jeanne when they made landfall in Florida..it seemed like the media was focused on Frances more then Jeanne and that they were more prepared for Frances as well.


It's because Frances was a more powerful storm and the second storm in two weeks to make landfall in Florida.

Frances


Jeanne
Member Since: August 11, 2008 Posts: 0 Comments: 2315
1148. troy1993
8:40 PM GMT on March 22, 2010
Hey Levi 32..What were the differences between Hurricane Frances and Jeanne when they made landfall in Florida..it seemed like the media was focused on Frances more then Jeanne and that they were more prepared for Frances as well.
Member Since: July 29, 2009 Posts: 0 Comments: 208
1147. Levi32
8:25 PM GMT on March 22, 2010
Our recent analog years did favor warmer waters off the west coast of North America, but they were all during a warm PDO, which will favor that kind of a pattern in the mid-latitudes whether it's a La Nina at the equator or not. This isn't the case anymore, as the PDO is going cold, so the pattern this year will likely not be the same.

Member Since: November 24, 2005 Posts: 635 Comments: 26547
1146. Patrap
8:21 PM GMT on March 22, 2010
Quoting AllStar17:




Updated for 2011 (just made):


Thats some cool Graphic for sure..

Those could sell..
Member Since: July 3, 2005 Posts: 420 Comments: 127549
1145. Levi32
8:19 PM GMT on March 22, 2010
The ECMWF, UKMET, and Japanese models don't agree with the CFS on the NE Pacific SSTs, and are more neutral to cold-biased along the west coast of North America.



Member Since: November 24, 2005 Posts: 635 Comments: 26547
1144. Drakoen
8:15 PM GMT on March 22, 2010
Quoting Levi32:
The CFS September heights show the 500mb ridge nosing into the eastern Gulf of Mexico, pushing the trough over the eastern U.S. back west of the Ohio Valley.



Very nice West-based negative NAO. Favors southeastern U.S. and GOM landfalls
Member Since: October 28, 2006 Posts: 57 Comments: 29887
1143. StormChaser81
8:13 PM GMT on March 22, 2010
Quoting Jeff9641:
Another amazing fact is that our water table in C FL is at summertime levels and our rainy season starts the end of May. With TS and hurricanes affecting FLorida this year we should top our yearly rainfall record in Orlando at 69.78" set back in 1969.


It can dry up very quick with summer time heat.
Member Since: August 11, 2008 Posts: 0 Comments: 2315
1142. StormChaser81
8:12 PM GMT on March 22, 2010
Quoting CybrTeddy:


Isidore, Isabel, Ivan, Ike, Ida, Igor? Anyone noticing a trend?


Well the trend might have to do with most times we have a I storm its in the peak of hurricane season. Of course the later half of the alphabet will have stronger storms, its in the peak of the season.
Member Since: August 11, 2008 Posts: 0 Comments: 2315
1141. Levi32
8:12 PM GMT on March 22, 2010
I'm taking these CFS forecasts with a grain of salt though....there is a problem with the SSTs in my opinion. Look at how warm it has the waters off the west coast of North America. I have doubts that this will shape up like it's seeing with the La Nina developing and the PDO going cold. The CFS is used to a warm PDO, and could easily make that error. If it is an error, there will be more troughing near the U.S. west coast than the model is showing.

Member Since: November 24, 2005 Posts: 635 Comments: 26547
1140. Levi32
8:09 PM GMT on March 22, 2010
The CFS September heights show the 500mb ridge nosing into the eastern Gulf of Mexico, pushing the trough over the eastern U.S. back west of the Ohio Valley.

Member Since: November 24, 2005 Posts: 635 Comments: 26547
1139. jeffs713
8:09 PM GMT on March 22, 2010
Quoting Drakoen:
CFS showing below normal pressures in the GOM for July:



*looks into my crystal ball*
I see a wet summer ahead for the gulf coast
Member Since: August 3, 2008 Posts: 16 Comments: 5871
1138. Drakoen
8:05 PM GMT on March 22, 2010
CFS August:

Member Since: October 28, 2006 Posts: 57 Comments: 29887
1137. Drakoen
8:04 PM GMT on March 22, 2010
CFS showing below normal pressures in the GOM for July:


Member Since: October 28, 2006 Posts: 57 Comments: 29887
1136. Levi32
7:58 PM GMT on March 22, 2010
Quoting Drakoen:


That does look over done. Right now I think the CFS has the best solution with an ENSO neutral with a cold bias; however, if we do slip into La Nina, then I think the ECMWF has a good handle at the rate at which the transition would occur.


I agree. I tend to lean towards the Euro as it picked up on the demise of this El Nino 2 months before the CFS did. In January the CFS still had us in an El Nino right until October, while the Euro had us going to central-neutral by the end of July:



Member Since: November 24, 2005 Posts: 635 Comments: 26547
1135. CybrTeddy
7:57 PM GMT on March 22, 2010
Quoting Jeff9641:


Earl, Igor, and Otto sound like intense storms and maybe Lisa.


Isidore, Isabel, Ivan, Ike, Ida, Igor? Anyone noticing a trend?
Member Since: July 8, 2005 Posts: 259 Comments: 23570
1134. Drakoen
7:53 PM GMT on March 22, 2010
Quoting Levi32:


The new March Japanese model forecast is even more bullish, though I think it is a bit overdone.



That does look over done. Right now I think the CFS has the best solution with an ENSO neutral with a cold bias; however, if we do slip into La Nina, then I think the ECMWF has a good handle at the rate at which the transition would occur.
Member Since: October 28, 2006 Posts: 57 Comments: 29887
1133. msgambler
7:52 PM GMT on March 22, 2010
Not quite spring yet. Was a tad bit chilly this morning, (low 40's), but supposed to turn around by mid week. Hoping for mid 70's. Am so looking foward to that.
Member Since: February 27, 2010 Posts: 0 Comments: 1125
1132. Levi32
7:51 PM GMT on March 22, 2010
Quoting Drakoen:


Very interesting situation setting up. Everything continues to point to a well-above average season. It looks like the ECMWF has gone colder with the La Nina developing at the height of hurricane season as you said.




The new March Japanese model forecast is even more bullish, though I think it is a bit overdone.

Member Since: November 24, 2005 Posts: 635 Comments: 26547
1131. xcool
7:50 PM GMT on March 22, 2010
Oh man WE IN trouble noww {{
Member Since: September 26, 2009 Posts: 2 Comments: 15620
1130. Levi32
7:48 PM GMT on March 22, 2010
Quoting msgambler:
Good afternoon, Levi, Drak, Patrap. Hope all are well today. Beautiful day on the Ms Coast, as far as I can tell from my hotel room window.


Afternoon gambler. Nice to hear spring is paying you a visit.
Member Since: November 24, 2005 Posts: 635 Comments: 26547
1129. Drakoen
7:47 PM GMT on March 22, 2010
Quoting Levi32:


If the La Nina does indeed get its act together during the height of the hurricane season, then high pressures over the eastern tropical Pacific will tend to deflect tropical waves and storms that enter the western Caribbean to the WNW or NW, more towards the Gulf of Mexico. This is the nature of La Nina, not allowing as many of the Atlantic tropical waves to cross central America and develop in the eastern Pacific instead.



Very interesting situation setting up. Everything continues to point to a well-above average season. It looks like the ECMWF has gone colder with the La Nina developing at the height of hurricane season as you said.


Member Since: October 28, 2006 Posts: 57 Comments: 29887
1128. msgambler
7:47 PM GMT on March 22, 2010
Good afternoon, Levi, Drak, Patrap. Hope all are well today. Beautiful day on the Ms Coast, as far as I can tell from my hotel room window.
Member Since: February 27, 2010 Posts: 0 Comments: 1125
1127. AstroHurricane001
7:47 PM GMT on March 22, 2010
Current weather report from my location in S. Ontario: 8.5C and ice pellets. It looks like the ice could get heavier.



They predicted some freezing rain for tonight yesteday afternoon, but it's too warm so there are ice pellets, the only type of ice precipitation that falls above freezing.
Member Since: August 30, 2008 Posts: 8 Comments: 2835
1126. AllStar17
7:45 PM GMT on March 22, 2010
Quoting Patrap:



Dis ting here called Google..

Its REALLY Amazing.
Google Images

And the List replaces the 04 Season ,not the 2005 Season as the image claims.

Can you edit the Original ?

er,for the archives.




Updated for 2011 (just made):
Member Since: June 29, 2009 Posts: 13 Comments: 5300
1125. Drakoen
7:44 PM GMT on March 22, 2010
Quoting Tropicsweatherpr:


What do you mean by this?

Pressures look to be 1mb slower.



I meant 1mb lower than average
Member Since: October 28, 2006 Posts: 57 Comments: 29887
1124. Levi32
7:43 PM GMT on March 22, 2010
Quoting Drakoen:
I see the new European climate forecast is out. Continuing to show SST between .5-1C above average in the MDR and anomalously higher precipitation with the axis of heaviest precipitation in WNW fashion across the MDR and into the Caribbean and Greater Antilles. Pressures look to be 1mb slower.


If the La Nina does indeed get its act together during the height of the hurricane season, then high pressures over the eastern tropical Pacific will tend to deflect tropical waves and storms that enter the western Caribbean to the WNW or NW, more towards the Gulf of Mexico. This is the nature of La Nina, not allowing as many of the Atlantic tropical waves to cross central America and develop in the eastern Pacific instead. This is what the Euro seems to be showing.

Member Since: November 24, 2005 Posts: 635 Comments: 26547
1123. Tropicsweatherpr
7:39 PM GMT on March 22, 2010
Quoting Drakoen:
I see the new European climate forecast is out. Continuing to show SST between .5-1C above average in the MDR and anomalously higher precipitation with the axis of heaviest precipitation in WNW fashion across the MDR and into the Caribbean and Greater Antilles. Pressures look to be 1mb slower.


What do you mean by this?

Pressures look to be 1mb slower.

Member Since: April 29, 2009 Posts: 75 Comments: 14009
1122. Drakoen
7:35 PM GMT on March 22, 2010
I see the new European climate forecast is out. Continuing to show SST between .5-1C above average in the MDR and anomalously higher precipitation with the axis of heaviest precipitation in WNW fashion across the MDR and into the Caribbean and Greater Antilles. Pressures look to be 1mb slower.
Member Since: October 28, 2006 Posts: 57 Comments: 29887
1120. xcool
7:26 PM GMT on March 22, 2010
Euro models VERY GOOD .SO LQQKING OUT
\\\\\\\\\\\\\\\ \\\\


Member Since: September 26, 2009 Posts: 2 Comments: 15620
1119. xcool
7:25 PM GMT on March 22, 2010
16-7-4 ----1-3 MAJOR LANDFALLS .
Member Since: September 26, 2009 Posts: 2 Comments: 15620
1118. HadesGodWyvern (Mod)
6:55 PM GMT on March 22, 2010


["Imani"]
Member Since: May 24, 2006 Posts: 50 Comments: 44740
1117. jeffs713
6:54 PM GMT on March 22, 2010
Quoting Patrap:



Dis ting here called Google..

Its REALLY Amazing.
Google Images


ok, I giggled. (no offense, AllStar17)
Member Since: August 3, 2008 Posts: 16 Comments: 5871
1116. HadesGodWyvern (Mod)
6:50 PM GMT on March 22, 2010
Mauritius Meteorological Services
Tropical Cyclone Advisory Number TWO
DEPRESSION TROPICALE 14-20092010
22:00 PM Réunion March 22 2010
===================================

At 18:00 PM UTC, Tropical Depression 14R (999 hPa) located at 11.6S 89.5E has 10 minute sustained winds of 30 knots with gusts of 45 knots. The depression is reported as moving south southwest at 6 knots.

Near Gale Force Winds
=======================
up to 95 NM in the northern semi-circle and up to 110 NM in the southwestern quadrant

Dvorak Intensity: 2.5/2.5/D1.0/24HRS

Forecast and Intensity
======================
12 HRS: 12.6S 88.9E - 35 knots (Tempête Tropicale Modereé)
24 HRS: 13.6S 87.9E - 40 knots (Tempête Tropicale Modereé)
48 HRS: 16.1S 86.0E - 60 knots (Forte Tempête Tropicale)
72 HRS: 19.3S 85.5E - 50 knots (Forte Tropicale Modereé)

Additional Information
========================
Dvorak analysis give DT 2.5 (curved band at 0.4 over recent infrared radar imagery), MET at 2.0 and PT at 2.5. FT based on PT. ASCAT pass at 15.13z shows some believable 30 knot winds in the northern semi circle and the southwestern quadrant (35-40 knot winds in the northwestern quadrant under deep convection). Based on the previous elements, system is upgraded to tropical depression status. System is currently on the western edge of a weak mid level ridge and just south of the deep (up to 500 hPa) west northwesterly monsoon flow that is established between the equator and 5.0S. Over the next three days, mid level ridge is building to the east of the system as a weakness remains in the subtropical ridge mainly east of 70.0E in the mid to upper level (despite, that close to the surface ridge extends quasi over the whole basin)

Wednesday night, a mid latitude trough is expected to be south of 20S and along 80E enhancing this weakness. COnsequently, system should continue its poleward track.

Available dynamical guidance are in fair agreement with that and current forecast is basically an update of the previous one. System should progressively pass under an upper level ridge with a weakening shear and rather good divergence. Low level inflow remains good poleward and should be better equatorwards. The system should intensify at a climatological rate with this favorable conditions. Thursday, increasing northwesterly shear and cooler waters near 20.0S should start a weakening trend on this system. So it has a 48 hour to 60 hour window for intensification.
Member Since: May 24, 2006 Posts: 50 Comments: 44740
1115. Patrap
6:50 PM GMT on March 22, 2010
Quoting AllStar17:


Where did you get my image?



Dis ting here called Google..

Its REALLY Amazing.
Google Images

And the List replaces the 04 Season ,not the 2005 Season as the image claims.

Can you edit the Original ?

er,for the archives.
Member Since: July 3, 2005 Posts: 420 Comments: 127549
1114. AllStar17
6:43 PM GMT on March 22, 2010
Quoting Patrap:


Colin replaces Charley from 04

Fiona replaces Frances from 04

Igor replaces Ivan

Julia replaces Jeanne,all retired from the 2004 season



Where did you get my image?
Member Since: June 29, 2009 Posts: 13 Comments: 5300
1113. stormwatcherCI
6:39 PM GMT on March 22, 2010
Quoting wunderkidcayman:
Hi guys we had a light shower not to long ago we need more
Lucky you. None up this way but North Side is black.
Member Since: October 9, 2008 Posts: 0 Comments: 8268
1112. BahaHurican
6:39 PM GMT on March 22, 2010
Quoting hcubed:


Unfortunately, the other 5 percent will be forced to pay for it...
At least the other 5 percent can afford it....

[sis boom bah!]
Member Since: October 25, 2005 Posts: 19 Comments: 21485
1111. stormwatcherCI
6:38 PM GMT on March 22, 2010
Quoting kimoskee:
Don't know if we can last until the summer for rain. It's chronic here in Jamaica.
Same here in Grand Cayman. Very dry.
Member Since: October 9, 2008 Posts: 0 Comments: 8268

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Jeff co-founded the Weather Underground in 1995 while working on his Ph.D. He flew with the NOAA Hurricane Hunters from 1986-1990.