Thunderstorms are forecast for Miami tomorrow, which could force the players to adopt the clever maneuver that Maria is deploying above.  Who do you think would enjoy the most success if they were required to play with an umbrella in one hand?  In case the inclement weather holds off, here are the previews and predictions for a busy Monday, which includes all of the women's fourth-round matches.ATP:Federer (1) vs. Serra:  The GOAT looked moderately motivated (at best) against Lapentti, but a perfunctory performance was good enough.  There's no reason to think that it won't be good enough against Serra, too.  Pick:  Federer.Zeballos vs. Berdych (16):  Although he's a notoriously streaky player, Berdych has been hitting the ball impressively over the last month.  Zeballos looked solid during a resounding win over Simon and could cause the Czech trouble with his eccentric style.  Still, it's hard to imagine him actually beating the much more powerful Berdych unless Berdych beats himself.  Pick:  Berdych.Verdasco (10) vs. Melzer (23):  Two more lefties battle in this round, which could be cloer than you might think; Melzer has posted some impressive results this year, including the Dubai semifinal.  Meanwhile, Verdasco came wildly unglued during a loss to Berdych at Indian Wells.  Both men can be mentally suspect and prone to implosions if their games aren't clicking.  If Verdasco plays at his usual level, he should win the crucial points and slip away with a tight victory.  Pick:  Verdasco.Baghdatis (25) vs. Cilic (7):  Long dormant, Baghdatis has awakened from a lengthy, injury-related slump this year.  Cilic won more matches than anyone at the beginning of 2010 but suffered a dismal second-round loss at Indian Wells while Baghdatis soared past Federer.  Can the Cypriot's charisma carry him past the Croat's consistency?  Pick:  Um, uh, Cilic?Fish vs. Lopez (29):  After upsetting Djokovic, Rochus succumbed to the much less redoubtable Bellucci (as I predicted below).  Will Fish suffer the same letdown?  His game is very similar to Lopez, so the match will come down to who is striking their first serve more impressively and creating opportunities to move forward.  The Miami crowd should help Fish as it did against Murray, although not as much as it would if he weren't in the breakfast slot on the schedule.  Pick:  Fish.Wawrinka (19) vs. Youzhny (13):  Check out the sensational one-handed backhands in this evenly balanced match, probably the most exciting of tomorrow's ATP schedule.  While Wawrinka has played little this year (see F for fatherhood) and probably will be rusty, Youzhny has displayed scintillating form by reaching the Dubai final and leading Russia to victory in Davis Cup.  He shouldn't need to crack a racket over his cranium as he did two years ago.  Pick:  Youzhny.Gonzalez (9) vs. Monaco (22):  Most renowned for his clay court expertise, the Argentine came within a set of the semifinals at Indian Wells, a superb result despite the early upsets in his section.  Like Wawrinka, Gonzalez may be a little rusty; he's played no hard-court tennis since the Australian Open.  However, the Chilean's powerful ground game should hit through Monaco's defenses as it has in all five of their previous encounters.  Pick:  Gonzalez.Petzschner vs. Soderling (6):  After Murray's untimely demise, this quarter has the Swede's name written all over it.  But can he capitalize on the opportunity?  He'll want to dispose of Petzschner as efficiently as possible in order to conserve energy for later rounds.  Pick:  Soderling.WTA:Kuznetsova (1) vs. Bartoli (13):  Far the superior athlete overall, Kuznetsova should be able to outlast the streaky Frenchwoman despite her eccentric, arhythmic style.  Bartoli's questionable serve will provide repeated opportunities for Kuznetsova to attack on the return.  Pick:  Kuznetsova.Wickmayer (12) vs. Bacsinszky:  The unseeded Swiss player has scoared a pair of strong wins over 8th-seeded Li Na and rising Slovenian star Polona Hercog, who recently reached the final in Acapulco.  On the other side, Wickmayer has cruised through her first two matches, dropping just ten games in four sets.  Despite a disappointing result in Indian Wells, she has been highly consistent this year and should soon find herself in the top 10  Pick:  Wickmayer.Venus (3) vs. Hantuchova (19):  If Venus serves well, there's little that the elegant but far less powerful Slovak can do to contain her.  Hantuchova does have the ability to exploit an erratic performance by the American, but she's undefeated since a disappointing exit in Melbourne.  Pick:  Venus.Shvedova vs. Radwanska (6):  The Russian-turned-Kazakh erased the still-injured Lisicki in a retirement-abbreviated encounter before edging past the increasingly formidable Petkovic.  She certainly has a chance to hit the Pole off the court, for she frequentlyhas headed the WTA's Power Index.  Nevertheless, one imagines that Radwanska will disrupt her one-dimensional style with intelligent modulations of pace and spin.  Pick:  Radwanska.Jankovic (7) vs. Stosur (9):  Despite their similar rankings, Jankovic dispatched Stosur comfortably in their Indian Wells semifinal.  If her return game can counterbalance the Australian's imposing serve, she'll be able to control most extended rallies, target Stosur's feeble backhand, and keep her pinned to the baseline rather than allowing her to showcase an excellent set of net skills.  Pick:  Jankovic.Clijsters (14) vs. Azarenka (4):  Probably the WTA match of the day, this round of 16 meeting opposes two of this event's former champions.  Both players have cruised through their first two matches in the tournament.  In their only meeting last year, Clijsters started strong, wobbled in the middle stages, and finished impressively after Azarenka lost control of her emotions.  She's been more erratic in 2010 than 2009 but remains mentally stronger than the Minx from Minsk.  Pick:  Heart says Azarenka, but head says Clijsters.Henin (W) vs. Zvonareva (11):  Like her compatriot, Henin confronts a dangerous yet mentally suspect opponent.  Zvonareva's balanced, textured game could allow her to exploit Henin's occasional spells of erratic play.  Nevertheless, her emotional fragility will hinder her against a sturdy competitor like Henin; although it's conceivable that the Russian could prevail, she'll have to maintain a high level of focus and intensity throughout the match.  Pick:  Henin.Pavlyuchenkova (22) vs. Wozniacki (2):  The Indian Wells runner-up has looked more than a little shaky in her first two matches, during the second of which she struggled with the humid conditions before unexpectedly regrouping.  She'll play later in the afternoon tomorrow, which will help her, but how much energy does she have left after a deep run in the desert and two epics here?  Pavlyuchenkova accumulated substantial court time herself, though, in a 3-hour, 12-minute second-round win over Paszek.  Wozniacki has produced mixed results against WTA veterans while flourishing against almost all of her peers.  All the same, if you're in the mood for a calculated risk, you might want to take a shot on Pavs.  Pick:  Wozniacki.(You might notice that all eight of my projected women's quarterfinalists from the pre-tournament preview reached the round of 16.  Thus, each of my picks for tomorrow corresponds with the original octet.)***We posted a 13-3 record in yesterday's predictions, including an 8-0 sweep of the WTA matches!  Let's hope that our luck continues tomorrow, especially with the ladies.  ;)